bluuebunny/crossref_metadata_2025 huggingface dataset:
ANALISIS PENCITRAAN ANTOLOGI PUISI LELAKI PENENUN CINTA KARYA TANITA LIASNA
Authors: Lubis Fheti Wulandari
Published: March 2020

Penelitian ini bertujuan untuk mengetahui pencitraan pada antologi puisi lelaki penenun cinta karya Tanita Liasna. Berdasarkan rumusan masalah dalam penelitian ini maka penelitian ini bertujuan untuk mengetahui pencitraan pada antologi puisi lelaki penenun cinta karya Tanita Liasna. Metode yang digunakan dalam penelitian ini adalah metode penelian kualitatif dengan cara analisis deskriptif . Alasan penulis menggunakan metode tersebut karena penulis berupaya mengetahui pencitraan apa saja yang terdapat dalam antologi puisi lelaki penenun cinta karya Tanita Liasna yang menjadi objek dalam penelitian ini. Instrument penelitiuan ini daalah dengan menggunakan teknik dokumentasi. Penggunaan teknik dokumentasi ini dilakukan dengan cara membaca sumber data berupa puisi dengan tujuan mengindetifikasi data sesuai dengan teori yang digunakan. Setelah memperoleh data penelitian ini selanjutnya analisis terhadap data penelitian dilakukan dengan teknik analisis isi. Proses analisis data dapat dilakukan dengan menguasai unsur fisik dan unsur bartin serta pencitraan pada antologi puisi lelaki penenun cinta karya Tanita Liasna. Hasil penelitian menunjukkan bahwa struktur fisik pada antologi puisi lelaki penenun cinta karya Tanita Liasna ini menggunakan diksi dan kata konkret yang bernada sindiran. Antologi puisi lelaki penenun cinta karya Tanita Liasna bertipografi dalam bait-bait lurus. Struktur batinnya dominan bertema romansa, selain itu puisi tersebut memiliki pencitraan penglihatan, Pendengaran, Gerak, Penciuman, Pengecapan.
Studi Eksperimen Karakteristik Mekanik Material Screw Press Kapasitas 10-14 Ton/Jam Di Lingkungan Pabrik Kelapa Sawit
Authors: Rinaldi Rinaldi , Pranoto Siswo , Afriza Rafasiro
Published: March 2020

Sawit merupakan salah satu tanaman penghasil minyak sawit (Cruide Palm Oil) dan inti sawit (Palm Kernel) dan menjadi primadona tanaman perkebunan yang menjadi sumber devisa non migas bagi Indonesia. Salah satu proses terpenting untuk mendapatkan minyak kelapa sawit ada pada mesin screw press. Mesin ini berfungsi  memeras buah sawit untuk mendapat minyak sawit. Mesin screw press ini sering terjadi kerusakan yaitu ausnya pisau press pada saat memeras buah sawit, hal ini disebabkan oleh  faktor lama pemakaian, perawatan, dan material screw press. Penelitian ini dilakukan untuk mengetahui karakteristik material screw press dengan melakukan beberapa pengujian, menganalisa gaya dan tegangan pada screw press. Pengujian yang dilakukan adalah: uji tarik, uji kekerasan, struktur mikro, dan komposisi kimia. dimana dari hasil pengujian yang dilakukan didapatkan hasil yaitu: tegangan tarik sebesar 78 kg/mm2 , keuletan screw 4,64%, sementara berdasarkan standar dari material screw press  tegangan tarik screw press  adalah 100 kg/mm2. Pengujian kekerasan dari tiga titik pengujian pada salah satu titik kekerasannya berbeda. Sedangkan gaya tekan yang terjadi pada screw adalah sebesar 264 kN/m2, dimana besarnya torsi 85,50 kN.m2, dan tegangan aksial screw sebesar 336,13 kN/m2. Dari hasil uji yang telah dilakukan dapat disimpulkan besarnya selisih tegangan tarik spesimen uji dengan standar pabrik sangat jauh, serta kekerasan permukaan screw  yang tidak sama sangat mempengarui tingkat aus pada material screw press.
Variasi Ukuran Puli Terhadap Produksi Hasil Alat Penumbuk Jengkol
Authors: Syawaldi Syawaldi
Published: March 2020

Penelitian  ini  bertujuan  untuk  memproduksi  emping  jengkol  berupa  kapasitas  dan  kualitas  dalam memproduksi emping jengkol dengan mesin penumbuk emping jengkol yang memvariasikan diameter puli yang berbeda-beda dengan variasi puli ukurans berdiameter 3 inchi, 4 inchi, 5 inchi, dan puli penggerak berdiameter 1,5 inchi. Hasil dari penelitian didapat daya motor penggerak adalah ¼ HP,kecepatan tumbukan rata-rata mesin yang menggunakan variasi puli penggerak diameter 1,5 inchi dengan puli yang digerakan berdiameter 3 inchi adalah 0,36 cm/s dengan waktu rata-rata tumbukan sebesar 10,65 detik,dan kapasitas produksi emping sebesar 333 emping/jam, sedangkan untuk varasi puli penggerak diameter 1,5 inchi dengan puli yang di gerakan diameter 4 inchi didapat kecepatan rata-rata tumbukan sebesar 0,27 cm/s dengan waktu rata-rata yang dibutuhkan mesin untuk menumbuk satu buah emping adalah sebesar 14,17 detik, dan kapasitas produksi emping sebesar 257 emping/jam, dan untuk hasil penelitian menggunakan mesin penumbuk variasi puli penggeraka diameter 1,5 inchi dengan puli yang di gerakan diameter 5 inchi didapatkan kecepatan rata-rata tumbukan sebesar 0,16 cm/s dengan waktu rata-rata tumbukan sebesar 23,91 detik, dengan kapasitas produksi emping sebesar 156 emping/jam. Dari penelitian yang telah dilakukan diperoleh hasil produksi yang baik dari ukuran puli 3 inchi dengan kecepatan rata-rata tumbukan sebesar 0,36 cm/s, dengan kapasitas 333 emping/jam.
Identifikasi Potensi Komoditi Unggulan dalam Pengoptimalan Fungsi Sarana Kargo Bandara Internasional Minangkabau (BIM)
Authors: Dermawan Dedi , Satriardi Satriardi
Published: March 2020

Ketersediaan data Potensi komoditi adalah salah satu faktor meningkat atau tidaknya investor masuk ke suatu daerah. Sumbar salah satu daerah yang potensial yang memiliki beragam komoditi baik ekspor dan lokal yang mampu meningkatkan perekonomian daerahnya. Namun saat ini Kargo Bandara Internasional Minangkabau terlihat pemanfaatan untuk komoditas sumber daya alam tersebut masih belum optimal. Penelitian ini diarahkan untuk mengetahui potensi-potensi komoditi Sumatera Barat pada saat ini dan yang akan datang dan menyusun serta mendeskripsikan data potensi kedalam suatu data base  (manual) berdasarkan pada jenis komoditi, daerah asal, daerah tujuan dan komoditi yang dikirim melalui transportasi udara dengan suatu metoda yang terstruktur dan ilmiah melalui Analisis Cluster dan diawali dengan mengestimasi potensi dengan metoda forcasting/peramalan.
Analisis Kekasaran Permukaan Benda Kerja Hasil Pembubutan dengan Variasi Jenis Material dan Pahat Potong
Authors: Istana Budi , Sunaryo Sunaryo , Kennedi Jon
Published: March 2020

The surface shape and roughness of a product produced by machine tools such as lathe plays an important role. This is due to the surface shape and roughness of the product related to friction, wear, lubrication system and so on. The machining process will determine the surface roughness at a certain level where the surface roughness can be used as a reference for evaluation of machining products. The surface roughness of a product does not have to be of little value. One product that is required to have a low surface roughness is the shaft. In the analysis of surface roughness, the steps taken are the selection of work material and the type of chisel that is often used in production workshops in Pekanbaru. Material of the workpiece used is ST41 and S45C while the type of cutting tool used is HSS and Widia Carbide. For the next process is the process of making workpieces with lathes with variations of types of cutting tool on each material workpiece. HSS chisel and carbide with ST41 steel material with rotation variation 300 rpm, 500 rpm and 840 rpm. In this material using HSS chisel it has increased roughness from 300 rpm (3,254 μm) to 500 rpm (5,425 μm) while 840 rpm (5,212 μm) has decreased roughness. otherwise the carbide has a roughness rate of 300 rpm (4,154 μm), 500 rpm (4,035 μm) and a round of 840 rpm (2,608 μm). HSS chisel and carbide with S45C steel material with rotation variation 300 rpm, 500 rpm and 840 rpm. In this material using HSS chisel has increased roughness from 300 rpm (5,778 μm) to 500 rpm (6,563 μm) while 840 rpm (5,712 μm) decreased roughness. otherwise the carbide has a roughness rate of 300 rpm (5.050 μm), 500 rpm (4,785 μm) and 840 rpm (4,116 μm).
Analisis Kelayakan Bisnis Kuliner “Sushi Kampung”
Authors: Dermawan Dedi , Satriardi Satriardi
Published: March 2020

Sushi merupakan ciri khas makanan rakyat Cina, sushi biasanya disajikan dengan beras jepang, rumput laut, telur ikan, dan sebagainya, tetapi harga yang ditawarkan sangatlah mahal sehingga tak seluruh kalangan dapat menikmatinya. Bukan hanya itu, sushi memiliki rasa yang asing jika dikonsumsi oleh orang yang belum pernah memakannya, sehingga terkadang sushi juga jarang dikonsumsi oleh masyarakat awam. “Sushi Kampung” merupakan produk olahan dengan rasa yang sudah biasa dinikmati oleh orang awam yaitu dengan varian rasa rendang, dendeng dan juga dapat dikemas dengan sushi yang digoreng  yang mana usaha ini akan dibangun di Jalan Melati, Kelurahan Padang Bulan, Kecamatan Senapelan, Kota Pekanbaru. Dari segi aspek pasar didapatkan market sebesar 69% dari pengunjung usaha lainnya, dengan alasan penasaran dengan rasa sushi tersebut. Dari segi aspek finansial, dilakukan uji kelayakan dengan melihat nilai NPV, AE, BCR, PBP, dan IRR usaha ini layak secara ekonomis.
Analisis Kelayakan Kapasitas Produksi dengan Metode RCCP (Studi Kasus PT. Sewangi Sejati Luhur)
Authors: Meirizha St Nova , Ardiansyah Ardiansyah
Published: March 2020

PT. Sewangi Sejati Luhur merupakan perusahaan manufaktur yang bergerak dibidang produksi CPO kelapa sawit sebagai komponen utama minyak goreng. Perusahaan ini sangat membutuhkan perencanaan kapasitas yang baik karena permintaan produknya yang terus bertambah dari tahun ke tahun, terutama perencanaan untuk produk yang menjadi andalan perusahaan yaitu produk CPO sawit. Kondisi yang terjadi saat ini ada beberapa stasiun kerja yang sumberdayanya menganggur pada saat-saat tertentu. Selain itu, ada juga beberapa stasiun kerja yang mesin atau tenaga kerjanya bekerja overload. Ini dapat dilihat dengan adanya antrian pada stasiun kerja tersebut. Oleh karena itu perlu dilakukan analisis kelayakan terhadap kapasitas produksi pada semua stasiun kerja yang ada dengan metode rough cut capacity planning (RCCP). Ada beberapa tahapan yang dilakukan dalam analisis kelayakan kapasitas. Tahap pertama adalah menghitung kapasitas tersedia setiap stasiun kerja. Selanjutnya dilakukan perhitungan kapasitas yang dibutuhkan setiap stasiun kerja. Tahapan terakhir adalah uji kelayakan kapasitas dengan membandingkan kapasitas tersedia dengan kapasitas yang dibutuhkan. Berdasarkan perhitungan Rough Cut Capacity Planning menggunakan metode CPOF dapat dilihat bahwa masih ada beberapa stasiun kerja yang menghasilkan nilai negatif untuk semua periode selama 12 bulan. Hal ini  menunjukkan bahwa kapasitas yang tersedia tidak dapat memenuhi kebutuhan kapasitas atau dengan kata lain kapasitas yang dibutuhkan jauh lebih besar dari kapasitas tersedia yang dimiliki oleh perusahaan.
Analisa Keandalan Kondensor dengan Menggunakan Debris Filter di PLTU Belawan
Authors: Ramadhan Andri
Published: March 2020

PLTU merupakan pembangkit listrik tenaga thermal yang mengubah energi kimia dalam bahan bakar menjadi energi listrik. Sistem air pendingin pada PLTU diperlukan secara terus menerus selama turbin uap beroperasi. Apabila aliran air pendingin terganggu atau hilang, maka operasi turbin uap harus dihentikan, karena turbin uap tidak dapat beroperasi tanpa aliran air pendingin ke kondensor masalah pada pipa aliran air pendingin pada kondensor seperti menumpuknya kotoran yang diakibatkan adanya biota laut antara lain teritip, kerang, ganggang, tiram dan jenis tumbuhan lainnya. Penyaring seperti Debris Filter diperlukan untuk menyaring kotoran pada air laut. Apabila terjadi kerusakan pada Debris Filter seperti rusaknya motor Debris dan kerusakan mekanis pada Filter akan mengakibatkan kotoran dapat lolos dan masuk ke kondensor, akibatnya tube-tube akan mengalami pluging (penyumbatan) dan bisa menyebabkan gangguan perpindahan panas yang secara langsung juga berakibat pada buruknya kevakuman pada kondensor. Hasil perhitungan menunjukan besarnya standar nilai tipikal koefisien perpindahan panas di dalam fouling sea water 1000-3000 W/m2 °C dan di mana besar nilai koefisien perpindahan panas di dalam fouling (hfi) yang dihitung masih didalam batas kewajaran atau dengan kata lain tergolong bersih yaitu 1276,82 W/m2·°C. Besarnya standar nilai tetapan dalam persamaan empiris faktor tanpa dimensi mengenai kebersihan adalah 0,85, di mana besar nilai yang diperoleh dari hasil perhitungan yaitu 0,75 masih tergolong bersih. Penggunaan debrish filter pada kondensor membuktikan bahwa keandalan kondensor pada pembangkit PLTU sektor Belawan Unit 3 masih dalam kondisi baik berdasarkan kebersihan pada tube.
Evaluasi Quantity Spare Parts dengan Pendekatan EOQ (Economic Order Quantity) PT. Kobexindo Tractors. Tbk Cabang Pekanbaru
Authors: Dermawan Dedi , Hidayah Wahyu
Published: March 2020

Kebutuhan Spare Parts unit Froklift Truck atau yang biasa disebut dengan Reach Truck saat ini dihadapkan pada sebuah risiko, tidak dapat memenuhi keinginan para pelanggannya. Persediaan bisa muncul ketika ada kebutuhan dan adanya sebuah perencanaan untuk mengadakan persediaan. Akibat yang ditimbulkan ketika sebuah perusahaan melakukan pengadaan tanpa ada perencanaan yaitu seringterjadinya tidak terjual akibat rendahnya jumlah permintaan sehingga mengakibatkan kinerja perusahaan menurun dan biaya yang tinggi. Teknik pengendalian persediaan akan memperkirakan berapa jumlah optimal tingkat persediaan yang diharuskan, serta kapan saatnya mulai mengadakan pemesanan kembali (reorder point). Perencanaan dengan pendekatan EOQ (Economic Order Quantity) merupakan solusi perencaaan persediaan yang optimal dalam memenuhi kebutuhan persediaan tetap lancar.
Analisis Postur Kerja Karyawan Kantor di Departemen Produksi Menggunakan Metode Rapid Office Strain Assesment (ROSA) (Studi Kasus : PT. Indah Kiat Pulp & Paper tbk)
Authors: Zen Zayyinul hayati , Mulyadi Agus
Published: March 2020

PT. Indah Kiat Pulp & Paper adalah salah satu perusahaan nasional yang bergerak dibidang produksi Pulp dan kertas. Perusahaan yang terletak di perawang ini memanfaatkan teknologi sebagai salah satu alat yang dapat mempermudah pekerjaan seperti komputer. Penelitian ini berfokus pada seksi Paper Machine#6 yang pekerjanya bekerja di ruangan. Pekerja selalu menggunakan komputer lebih dari 8 jam/hari. Penelitian awal dengan cara menyebarkan kuesioner Standart Nordic Questionnaire (SNQ) untuk mengetahui keluhan yang dirasakan karyawan. Dari kuesioner banyak pekerja yang merasakan sakit pada punggung, pantat, pinggang, paha dan pergelangan tangan. Keluhan tersebut dapat diminimalkan dengan cara mengetahui dan mengidentifikasi postur kerja pada karyawan dalam menggunakan komputer dengan menggunakan metode Rapid Office Strain Assesment (ROSA). ROSA merupakan salah satu metode khusus ergonomi perkantoran, dimana penilaiannya dirancang untuk mengukur resiko yang terkait dengan penggunaan komputer. Dengan metode ini maka dapat diketahui apakah postur kerja pada karyawan kantor PT. Indah Kiat Pulp & Paper Tbk masih dibatas yang dianggap aman. Hasil penilaian postur kerja dengan ROSA yaitu postur kerja beresiko, pada keadaan tersebut jika dilakukan terus menerus tanpa ada perbaikan maka dapat meyebabkan cidera yang berdampak pada kinerja dan produktivitas karyawan. Oleh sebab itu perlu direkomendasikan ke perusahaan yang bersangkutan dengan melakukan perbaikan. perbaikan yang dilakukan untuk mengurangi tingkat resiko yang dirasakan dengan cara perbaikan fasilitas kerja yang digunakan dengan standar ergonomi dan penggunaan jam isitirahat dengan peregangan otot atau relaksasi.
PLC-HMI BASED SIMULATION of PV CELL and ARRAY BEHAVIOR
Authors: Fadhil Maytham , Mahmood Jawad
Published: March 2020

This paper presents the PLC-HMI based simulation of electrical-based PV cell/array model in laboratory platform to give the opportunity to students and users who haven't clear knowledge to study PV cell and array behavior with respect to change of environment conditions and electrical parameters. This simulation process covers the cell models under ideal and non-ideal ones. In non-ideal one, the series resistance and the shunt resistance are covered.
Design and Analysis of a Single-Band Printed Rectenna Circuit at WiFi Frequency for Microwave Power Transmission
Authors: Salih Ahmad , Abdullah Abdulkareem
Published: March 2020

In this paper, a single-band printed rectenna of size (45×36) mm2 has been designed and analyzed to work at WiFi frequency of 2.4 GHz for wireless power transmission. The antenna part of this rectenna has the shape of question mark patch along with an inverted L-shape resonator and printed on FR4 substrate. The rectifier part of this rectenna is also printed on FR4 substrate and consisted of impedance matching network, AC-to-DC conversion circuit and a DC filter. The design and simulation results of this rectenna have been done with the help of CST 2018 and ADS 2017 software packages. The maximum conversion efficiency obtained by this rectenna is found as 57.141% at an input power of 2 dBm and a load of 900 Ω.
Phase Swapping Load Balancing Algorithms, Comprehensive Survey
Authors: Al-Kharsan Ibrahim , Marhoon Ali , Mahmood Jawad
Published: March 2020

The power quality nowadays of the low voltage distribution system is vital for the utility and the consumer at the same time. One disturbing issue affected the quality conditions in the radial distribution system is load balancing. This survey paper is looking most the articles that deal with the phase nodal and lateral phase swapping because it is the efficient and direct method to maintain the current and voltage in balance situation, lead to a suitable reduction in the losses and preventing the wrong tripping of the protective relays.
An Efficient Mathematical Approach for an Indoor Robot Localization System
Authors: AL-Forati Israa , Rashid Abdulmuttalib , Al-Assfor Fatemah
Published: March 2020

In a counterfeit clever control procedure, another productive methodology for an indoor robot localization framework is arranged. In this paper, a new mathematic calculation for the robot confinement framework utilizing light sensors is proposed. This procedure takes care of the issue of localization (position recognizing) when utilizing a grid of LEDs distributed uniformly in the environment, and a multi-portable robot outfitted with a multi-LDRs sensor and just two of them activate the visibility robot. The proposed method is utilized to assess the robot's situation by drawing two virtual circles for each two LDR sensors; one of them is valid and the other is disregarded according to several suggested equations. The midpoint of this circle is assumed to be the robot focus. The new framework is simulated on a domain with (n*n) LEDs exhibit. The simulation impact of this framework shows great execution in the localization procedure.
Nonlinear Physiological Model of Insulin-Glucose Regulation System in Type 1 Diabetes Mellitus
Authors: Ali Ahmed , Tahir Fadhil
Published: March 2020

Mathematical modeling is very effective method to investigate interaction between insulin and glucose. In this paper, a new mathematical model for insulin-glucose regulation system is introduced based on well-known Lokta-Volterra model. Chaos is a common property in complex biological systems in the previous studies. The results here are in accordance with previous ones and indicating that insulin-glucose regulating system has many dynamics in different situations. The overall result of this paper may be helpful for better understanding of diabetes mellitus regulation system including diseases such as hyperinsulinemia and Type1 DM.
ANALISIS NERACA AIR DAERAH ALIRAN SUNGAI BOLANGO
Authors: Mopangga Syafrudin
Published: March 2020

ABSTRAK

Air bertransformasi melalui daur hidrologi yang dikenal sebagai sistim hidrologi dan pada Daerah Aliran Sungai (DAS) air diterima dari curah hujan yang kemudian memprosesnya sesuai dengan karakteristiknya menjadi aliran.  Degradasi dan kerusakan sistem hidrologi DAS merupakan salah satu aspek kekritisan daerah aliran sungai, salah satu kerusakan sistem hidrologi DAS adalah terjadinya kekurangan air di musim kering dan meluapnya air pada musim penghujan. Untuk mengetahui kebutuhan air di daerah aliran sungai Bolango, jumlah besar debit ketersediaan air di daerah aliran sungai Bolango dan neraca air di daerah aliran sungai Bolango. Tahapan penelitian melalui Pengambilan Data, Analisa Curah Hujan, Analisa Debit Air, Perhitungan Kebutuhan Air dan Perhitungan Analisis Neraca Air DAS Bolango. Debit minimum pada bulan september dan debit maksimum pada bulan april. Untuk memenuhi kebutuhan air domestik dan non domestik masyarakat  terutama yang ada di derah Kota Gorontalo perhitungan ketersediaan air ini sangat diperlukan untuk menentukan neraca air pada Daerah Aliran Sungai Bolango. 1. Debit inflow berkisar antara : 14,42 /detik s/d 26,15 /detik, 2. Debit inflow maksimum (Desember) : 26,15 /detik, 3. Debit inflow minimum (September) : 14,42 /detik.

 

Kata Kunci: Hidrologi, Curah Hujan, Debit Air, & Neraca Air
Occurrence and Architecture of Kepler Planetary Systems as Functions of Stellar Mass and Effective Temperature
Authors: Yang Jia-Yi , Xie Ji-Wei , Zhou Ji-Lin
Published: March 2020

The Kepler mission has discovered thousands of exoplanets around various stars with different spectral types (M, K, G, and F) and thus different masses and effective temperatures. Previous studies have shown that the planet occurrence rate, in terms of the average number of planets per star, drops with increasing stellar effective temperature (T
eff). In this paper, with the final Kepler Data Release (DR25) catalog, we revisit the relation between stellar effective temperature (as well as mass) and planet occurrence, but in terms of the fraction of stars with planets and the number of planets per planetary system (i.e., planet multiplicity). We find that both the fraction of stars with planets and planet multiplicity decrease with increasing stellar temperature and mass. Specifically, about 75% late-type stars (T
eff < 5000 K) have Kepler-like planets with an average planet multiplicity of ∼2.8, while for early-type stars (T
eff > 6500 K) this fraction and the average multiplicity fall down to ∼35% and ∼1.8, respectively. The decreasing trend in the fraction of stars with planets is very significant with ΔAIC > 30, though the trend in planet multiplicity is somewhat tentative with ΔAIC ∼ 5. Our results also allow us to derive the dispersion of planetary orbital inclinations in relationship with stellar effective temperature. Interestingly, it is found to be similar to the well-known trend between obliquity and stellar temperature, indicating that the two trends might have a common origin.
Photometric Biases in Modern Surveys
Authors: Portillo Stephen K. N. , Speagle Joshua S. , Finkbeiner Douglas P.
Published: March 2020

Many surveys use maximum-likelihood (ML) methods to fit models when extracting photometry from images. We show that these ML estimators systematically overestimate the flux as a function of the signal-to-noise ratio and the number of model parameters involved in the fit. This bias is substantially worse for resolved sources: while a 1% bias is expected for a 10σ point source, a 10σ resolved galaxy with a simplified Gaussian profile suffers a 2.5% bias. This bias also behaves differently depending how multiple bands are used in the fit: simultaneously fitting all bands leads the flux bias to become roughly evenly distributed between them, while fixing the position in “non-detection” bands (i.e., forced photometry) gives flux estimates in those bands that are biased low, compounding a bias in derived colors. We show that these effects are present in idealized simulations, outputs from the Hyper Suprime-Cam fake-object pipeline (SynPipe), and observations from Sloan Digital Sky Survey Stripe 82. Prescriptions to correct for the ML bias in flux, and its uncertainty, are provided.
Analysis of Membership Probability in Nearby Young Moving Groups with Gaia DR2
Authors: Ujjwal K. , Kartha Sreeja S. , Mathew Blesson , Manoj P. , Narang Mayank
Published: March 2020

We analyze the membership probability of young stars belonging to nearby moving groups with Gaia DR2 data. The sample of 1429 stars was identified from “The Catalog of Suspected Nearby Young Moving Group Stars.” Good-quality parallax and proper motion values were retrieved for 890 stars from the Gaia DR2 database. The analysis for membership probability is performed in the framework of the LACEwING algorithm. From the analysis it is confirmed that 279 stars do not belong to any of the known moving groups. We estimated the U, V, W space velocity values for 250 moving group members, which were found to be more accurate than previous values listed in the literature. The velocity ellipses of all the moving groups are well constrained within the “good box,” a widely used criterion to identify moving group members. The age of moving group members are uniformly estimated from the analysis of the Gaia color–magnitude diagram with MIST isochrones. We found a spread in the age distribution of stars belonging to some moving groups, which needs to be understood from further studies.
Probing UV-sensitive Pathways for CN and HCN Formation in Protoplanetary Disks with the Hubble Space Telescope
Authors: Arulanantham Nicole , France Kevin , Cazzoletti Paolo , Miotello Anna , Manara Carlo F. , Schneider P. Christian , Hoadley Keri , van Dishoeck Ewine F. , Günther Hans Moritz
Published: March 2020

The UV radiation field is a critical regulator of gas-phase chemistry in surface layers of disks around young stars. In an effort to understand the relationship between photocatalyzing UV radiation fields and gas emission observed at infrared and submillimeter wavelengths, we present an analysis of new and archival Hubble Space Telescope (HST), Spitzer, ALMA, IRAM, and SMA data for five targets in the Lupus cloud complex and 14 systems in Taurus-Auriga. The HST spectra were used to measure Lyα and far-UV (FUV) continuum fluxes reaching the disk surface, which are responsible for dissociating relevant molecular species (e.g., HCN, N2). Semi-forbidden C ii] λ2325 and UV-fluorescent H2 emission were also measured to constrain inner disk populations of C+ and vibrationally excited H2. We find a significant positive correlation between 14 μm HCN emission and fluxes from the FUV continuum and C ii] λ2325, consistent with model predictions requiring N2 photodissociation and carbon ionization to trigger the main CN/HCN formation pathways. We also report significant negative correlations between submillimeter CN emission and both C ii] and FUV continuum fluxes, implying that CN is also more readily dissociated in disks with stronger FUV irradiation. No clear relationships are detected between either CN or HCN and Lyα or UV-H2 emission. This is attributed to the spatial stratification of the various molecular species, which span several vertical layers and radii across the inner and outer disk. We expect that future observations with the James Webb Space Telescope will build on this work by enabling more sensitive IR surveys than were possible with Spitzer.
Assessment of Astronomical Images Using Combined Machine-learning Models
Authors: Teimoorinia H. , Kavelaars J. J. , Gwyn S. D. J. , Durand D. , Rolston K. , Ouellette A.
Published: March 2020

We present a two-component machine-learning-based approach for classifying astronomical images by data quality via an examination of sources detected in the images and image pixel values from representative sources within those images. The first component, which uses a clustering algorithm, creates a proper and small fraction of the image pixels to determine the quality of the observation. The representative images (and associated tables) are ∼800 times smaller than the original images, significantly reducing the time required to train our algorithm. The useful information in the images is preserved, permitting them to be classified into different categories, but the required storage is reduced. The second component, which is a deep neural network model, classifies the representative images. Using ground-based telescope imaging data, we demonstrate that the method can be used to separate “usable” images from those that present some problems for scientific projects—such as images that were taken in suboptimal conditions. This method uses two different data sets as input to a deep model and provides better performance than if we only used the images’ pixel information. The method may be used in cases where large and complex data sets should be examined using deep models. Our automated classification approach achieves 97% agreement when compared to classification generated via manual image inspection. We compare our method with traditional results and show that the method improves the results by about 10%, and also presents more comprehensive outcomes.
A Ringed Pole-on Outflow from DO Tauri Revealed by ALMA
Authors: Fernández-López Manuel , Zapata Luis A. , Rodríguez Luis F. , Vazzano María M. , Guzmán Andrés E. , López Rosario
Published: March 2020

We present new Atacama Large Millimeter/submillimeter Array (ALMA) Band 6 observations including the CO(2−1) line and 1.3 mm continuum emission from the surroundings of the young stellar object DO Tauri. The ALMA CO molecular data show three different series of rings at different radial velocities. These rings have radii around 220 and 800 au. We make individual fits to the rings and note that their centers are aligned with DO Tauri and its optical high-velocity jet. In addition, we notice that the velocity of these structures increases with the separation from the young star. We discuss the data under the hypothesis that the rings represent velocity cuts through three outflowing shells that are possibly driven by a wide-angle wind, dragging the environment material along a direction close to the line of sight (i = 19°). We estimate the dynamical ages, the mass, the momentum, and the energy of each individual outflow shell and those of the whole outflow. The results are in agreement with those found in outflows from Class II sources. We make a rough estimate for the size of the jet/wind launching region, which needs to be of ≲15 au. We report the physical characteristics of DO Tauri’s disk continuum emission (almost face-on and with a projected major axis in the north–south direction) and its velocity gradient orientation (north–south), indicative of disk rotation for a 1–2 M
⊙ central star. Finally, we show a Hubble Space Telescope [S ii] image of the optical jet and report a measurement of its orientation in the plane of the sky.
Temperatures and Metallicities of M Dwarfs in the APOGEE Survey
Authors: Birky Jessica , Hogg David W. , Mann Andrew W. , Burgasser Adam
Published: March 2020

M dwarfs have enormous potential for our understanding of structure and formation on both Galactic and exoplanetary scales through their properties and compositions. However, current atmosphere models have limited ability to reproduce spectral features in stars at the coolest temperatures (T
eff < 4200 K) and to fully exploit the information content of current and upcoming large-scale spectroscopic surveys. Here we present a catalog of spectroscopic temperatures, metallicities, and spectral types for 5875 M dwarfs in the Apache Point Observatory Galactic Evolution Experiment (APOGEE) and Gaia-DR2 surveys using The Cannon: a flexible, data-driven spectral-modeling and parameter-inference framework demonstrated to estimate stellar-parameter labels (

,

,

, and detailed abundances) to high precision. Using a training sample of 87 M dwarfs with optically derived labels spanning

calibrated with bolometric temperatures, and

dex calibrated with FGK binary metallicities, we train a two-parameter model with predictive accuracy (in cross-validation) to 77 K and 0.09 dex respectively. We also train a one-dimensional spectral classification model using 51 M dwarfs with Sloan Digital Sky Survey optical spectral types ranging from M0 to M6, to predictive accuracy of 0.7 types. We find Cannon temperatures to be in agreement to within 60 K compared to a subsample of 1702 sources with color-derived temperatures, and Cannon metallicities to be in agreement to within 0.08 dex metallicity compared to a subsample of 15 FGK+M or M+M binaries. Finally, our comparison between Cannon and APOGEE pipeline (ASPCAP DR14) labels finds that ASPCAP is systematically biased toward reporting higher temperatures and lower metallicities for M dwarfs.
SN 2010kd: Photometric and Spectroscopic Analysis of a Slow-decaying Superluminous Supernova
Authors: Kumar Amit , Pandey Shashi Bhushan , Konyves-Toth Reka , Staten Ryan , Vinko Jozsef , Wheeler J. Craig , Zheng WeiKang , Filippenko Alexei V. , Kehoe Robert , Quimby Robert , Fang Yuan , Akerlof Carl , McKay Tim A. , Chatzopoulos Emmanouil , Thomas Benjamin P. , Dhungana Govinda , Aryan Amar , Dastidar Raya , Gangopadhyay Anjasha , Gupta Rahul , Misra Kuntal , Kumar Brajesh , Brahme Nameeta , Buckley David
Published: March 2020

This paper presents data and analysis of SN 2010kd, a low-redshift (z = 0.101) H-deficient superluminous supernova (SLSN), based on ultraviolet/optical photometry and optical spectroscopy spanning between −28 and +194 days relative to B-band maximum light. The B-band light-curve comparison of SN 2010kd with a subset of well-studied SLSNe I at comparable redshifts indicates that it is a slow-decaying PTF12dam-like SLSN. Analytical light-curve modeling using the Minim code suggests that the bolometric light curve of SN 2010kd favors circumstellar matter interaction for the powering mechanism. SYNAPPS modeling of the early-phase spectra does not identify broad H or He lines, whereas the photospheric-phase spectra are dominated by O i, O ii, C ii, C iv, and Si ii, in particular the presence of both low- and high-velocity components of O ii and Si ii lines. The nebular-phase spectra of SN 2010kd are dominated by O i and Ca ii emission lines similar to those seen in other SLSNe I. The line velocities in SN 2010kd exhibit flatter evolution curves similar to SN 2015bn but with comparatively higher values. SN 2010kd shows a higher single-zone local thermodynamic equilibrium temperature in comparison to PTF12dam and SN 2015bn, and it has an upper O i ejected mass limit of ∼10 M
⊙. The host of SN 2010kd is a dwarf galaxy with a high star formation rate (∼0.18 ± 0.04 M
⊙ yr−1) and extreme emission lines.
The HSC-SSP Transient Survey: Implications from Early Photometry and Rise Time of Normal Type Ia Supernovae
Authors: Jiang Ji-an , Yasuda Naoki , Maeda Keiichi , Doi Mamoru , Shigeyama Toshikazu , Tominaga Nozomu , Tanaka Masaomi , Moriya Takashi J. , Takahashi Ichiro , Suzuki Nao , Morokuma Tomoki , Nomoto Ken’ichi
Published: March 2020

With a booming number of Type Ia supernovae (SNe Ia) discovered within a few days of their explosions, a fraction of SNe Ia that show luminosity excess in the early phase (early-excess SNe Ia) have been confirmed. In this article, we report early-phase observations of seven photometrically normal SNe Ia (six early detections and one deep non detection limit) at the COSMOS field through a half-year transient survey as a part of the Hyper Suprime-Cam Subaru Strategic Program (HSC SSP). In particular, a blue light-curve excess was discovered for HSC17bmhk, a normal SN Ia with rise time longer than 18.8 days, during the first four days after the discovery. The blue early excess in optical wavelength can be explained not only by interactions with a nondegenerate companion or surrounding dense circumstellar matter but also radiation powered by radioactive decays of 56Ni at the surface of the SN ejecta. Given the growing evidence of the early-excess discoveries in normal SNe Ia that have longer rise times than the average, and a similarity in the nature of the blue excess to a luminous SN Ia subclass, we infer that early excess discovered in HSC17bmhk and other normal SNe Ia are most likely attributed to radioactive 56Ni decay at the surface of the SN ejecta. In order to successfully identify normal SNe Ia with early excess similar to that of HSC17bmhk, early UV photometries or high-cadence blue-band surveys are necessary.
Potential Vorticity Mixing in a Tangled Magnetic Field
Authors: Chen Chang-Chun , Diamond Patrick H.
Published: March 2020

A theory of potential vorticity (PV) mixing in a disordered (tangled) magnetic field is presented. The analysis is in the context of β-plane MHD, with a special focus on the physics of momentum transport in the stably stratified, quasi-2D solar tachocline. A physical picture of mean PV evolution by vorticity advection and tilting of magnetic fields is proposed. In the case of weak field perturbations, quasi-linear theory predicts that the Reynolds and magnetic stresses balance as turbulence Alfvénizes for a larger mean magnetic field. Jet formation is explored quantitatively in the mean field–resistivity parameter space. However, since even a modest mean magnetic field leads to large magnetic perturbations for large magnetic Reynolds number, the physically relevant case is that of a strong but disordered field. We show that numerical calculations indicate that the Reynolds stress is modified well before Alfvénization—i.e., before fluid and magnetic energies balance. To understand these trends, a double-average model of PV mixing in a stochastic magnetic field is developed. Calculations indicate that mean-square fields strongly modify Reynolds stress phase coherence and also induce a magnetic drag on zonal flows. The physics of transport reduction by tangled fields is elucidated and linked to the related quench of turbulent resistivity. We propose a physical picture of the system as a resisto-elastic medium threaded by a tangled magnetic network. Applications of the theory to momentum transport in the tachocline and other systems are discussed in detail.
Distribution of Water Vapor in Molecular Clouds. II
Authors: Melnick Gary J. , Tolls Volker , Snell Ronald L. , Kaufman Michael J. , Bergin Edwin A. , Goicoechea Javier R. , Goldsmith Paul F. , González-Alfonso Eduardo , Hollenbach David J. , Lis Dariusz C. , Neufeld David A.
Published: March 2020

The depth-dependent abundance of both gas-phase and solid-state water within dense, quiescent, molecular clouds is important to both the cloud chemistry and gas cooling. Where water is in the gas phase, it is free to participate in the network of ion-neutral reactions that lead to a host of oxygen-bearing molecules, and its many ortho- and para-energy levels make it an effective coolant for gas temperatures greater than 20 K. Where water is abundant as ice on grain surfaces, and unavailable to cool the gas, significant amounts of oxygen are removed from the gas phase, suppressing the gas-phase chemical reactions that lead to a number of oxygen-bearing species, including O2. Models of far-UV (FUV)-illuminated clouds predict that the gas-phase water abundance peaks in the range

∼ 3 and 8 mag of the cloud surface, depending on the gas density and FUV field strength. Deeper within such clouds, water is predicted to exist mainly as ice on grain surfaces. More broadly, these models are used to analyze a variety of other regions, including outflow cavities associated with young stellar objects and the surface layers of protoplanetary disks. In this paper, we report the results of observational tests of FUV-illuminated cloud models toward the Orion Molecular Ridge and Cepheus B using data obtained from the Herschel Space Observatory and the Five College Radio Astronomy Observatory. Toward Orion, 2220 spatial positions were observed along the face-on Orion Ridge in the H2O 1

– 101 557 GHz and NH3
J, K = 1,0–0,0 572 GHz lines. Toward Cepheus B, two strip scans were made in the same lines across the edge-on ionization front. These new observations demonstrate that gas-phase water exists primarily within a few magnitudes of dense cloud surfaces, strengthening the conclusions of an earlier study based on a much smaller data set, and indirectly supports the prediction that water ice is quite abundant in dense clouds.
A Deep View into the Nucleus of the Sagittarius Dwarf Spheroidal Galaxy with MUSE. II. Kinematic Characterization of the Stellar Populations
Authors: Alfaro-Cuello M. , Kacharov N. , Neumayer N. , Bianchini P. , Mastrobuono-Battisti A. , Lützgendorf N. , Seth A. C. , Böker T. , Kamann S. , Leaman R. , Watkins L. L. , van de Ven G.
Published: March 2020

The Sagittarius dwarf spheroidal galaxy is in an advanced stage of disruption but still hosts its nuclear star cluster (NSC), M54, at its center. In this paper, we present a detailed kinematic characterization of the three stellar populations present in M54: young metal-rich (YMR); intermediate-age metal-rich (IMR); and old metal-poor (OMP), based on the spectra of ∼6500 individual M54 member stars extracted from a large Multi-Unit Spectroscopic Explorer (MUSE)/Very Large Telescope data set. We find that the OMP population is slightly flattened with a low amount of rotation (∼0.8 km s−1) and with a velocity dispersion that follows a Plummer profile. The YMR population displays a high amount of rotation (∼5 km s−1) and a high degree of flattening, with a lower and flat velocity dispersion profile. The IMR population shows a high but flat velocity dispersion profile, with some degree of rotation (∼2 km s−1). We complement our MUSE data with information from Gaia DR2 and confirm that the stars from the OMP and YMR populations are comoving in 3D space, suggesting that they are dynamically bound. While dynamical evolutionary effects (e.g., energy equipartition) are able to explain the differences in velocity dispersion between the stellar populations, the strong differences in rotation indicate different formation paths for the populations, as supported by an N-body simulation tailored to emulate the YMR–OMP system. This study provides additional evidence for the M54 formation scenario proposed in our previous work, where this NSC formed via GC accretion (OMP) and in situ formation from gas accretion in a rotationally supported disk (YMR).
Newly Improved Ionization Corrections for the Neutral Interstellar Medium: Enabling Accurate Abundance Determinations in Star-forming Galaxies throughout the Universe*
Authors: Hernandez Svea , Aloisi Alessandra , James Bethan L. , Ferland Gary J. , Fox Andrew J. , Tosi Monica , Tumlinson Jason
Published: March 2020

Studies measuring the chemical abundances of the neutral gas in star-forming galaxies (SFGs) require ionization correction factors (ICFs) to accurately measure their metal contents. In the work presented here, we calculate newly improved ICFs for a sample of SFGs. These new corrections include both the contaminating ionized gas along the line of sight (

) and unaccounted for higher ionization stages in the neutral gas (

). We make use of recently acquired spectroscopic observations taken with the Cosmic Origins Spectrograph on board Hubble to measure column densities for Fe ii and Fe iii. Using the Fe iii/Fe ii ratios as well as other physical properties (i.e., log[

], N(H i), T, and Z), we generate ad hoc photoionization models with CLOUDY to quantify the corrections required for each of the targets. We identify a luminosity threshold of log[

] ∼ 40.75 erg s−1 above which the

values for nitrogen are relatively higher (

−0.7) than those for the rest of the elements (

). This behavior indicates that, for the high UV luminosity objects, N ii is found in non-negligible quantities in the neutral gas, making these

corrections critical for determining the true abundances in the interstellar medium. In addition, we calculate ICFs from a uniform grid of models covering a wide range of physical properties typically observed in studies of SFGs and extragalactic H ii regions. We provide the community with tabulated ICF values for the neutral gas abundances measured from a variety of environments and applicable to chemical studies of the high-redshift universe.
The Evolving AGN Duty Cycle in Galaxies Since z ∼ 3 as Encoded in the X-Ray Luminosity Function
Authors: Delvecchio I. , Daddi E. , Aird J. , Mullaney J. R. , Bernhard E. , Grimmett L. P. , Carraro R. , Cimatti A. , Zamorani G. , Caplar N. , Vito F. , Elbaz D. , Rodighiero G.
Published: March 2020

We present a new modeling of the X-ray luminosity function (XLF) of active galactic nuclei (AGNs) out to z ∼ 3, dissecting the contributions of main-sequence (MS) and starburst (SB) galaxies. For each galaxy population, we convolved the observed galaxy stellar mass (M
⋆) function with a grid of M
⋆-independent Eddington ratio (λ
EDD) distributions, normalized via empirical black hole accretion rate (BHAR) to star formation rate (SFR) relations. Our simple approach yields an excellent agreement with the observed XLF since z ∼ 3. We find that the redshift evolution of the observed XLF can only be reproduced through an intrinsic flattening of the λ
EDD distribution and with a positive shift of the break λ*, consistent with an antihierarchical behavior. The AGN accretion history is predominantly made by massive (1010 < M
⋆ < 1011
M
⊙) MS galaxies, while SB-driven BH accretion, possibly associated with galaxy mergers, becomes dominant only in bright quasars, at log(L
X/erg s−1) > 44.36 + 1.28 × (1 + z). We infer that the probability of finding highly accreting (λ
EDD > 10%) AGNs significantly increases with redshift, from 0.4% (3.0%) at z = 0.5%–6.5% (15.3%) at z = 3 for MS (SB) galaxies, implying a longer AGN duty cycle in the early universe. Our results strongly favor a M
⋆-dependent ratio between BHAR and SFR, as BHAR/SFR ∝ 

, supporting a nonlinear BH buildup relative to the host. Finally, this framework opens potential questions on super-Eddington BH accretion and different λ
EDD prescriptions for understanding the cosmic BH mass assembly.
Radio Sources Associated with Optical Galaxies and Having Unresolved or Extended Morphologies (ROGUE). I. A Catalog of SDSS Galaxies with FIRST Core Identifications
Authors: Kozieł-Wierzbowska Dorota , Goyal Arti , Żywucka Natalia
Published: March 2020

We present the catalog of Radio sources associated with Optical Galaxies and having Unresolved or Extended morphologies I (ROGUE I), consisting of 32,616 spectroscopically selected galaxies. It is the largest handmade catalog of this kind, obtained by cross-matching galaxies from the Sloan Digital Sky Survey (SDSS) Data Release 7 and radio sources from both the First Images of Radio Sky at Twenty Centimetre (FIRST) survey and the NRAO Very Large Array Sky Survey, without imposing a limit on the radio flux densities. The catalog provides a visual classification of radio and optical morphologies of galaxies presenting a FIRST core within 3″ of the optical position. The radio morphological classification is performed by examining the radio–optical overlays of linear sizes equal to 1 Mpc at the source distance, while the 120″ image snapshots from the SDSS database are used for optical classification. The results of our search are as follows: (i) single-component unresolved and elongated radio sources constitute the major group in the ROGUE I catalog (∼90%), and ∼8% exhibit extended morphologies; (ii) samples of 269, 730, and 115 Fanaroff–Riley (FR) type I, II, and hybrid galaxies, respectively, are presented; (iii) we report 55 newly discovered giant/possible giant, 16 double–double, 9 X-shaped, and 25 Z-shaped radio sources; (iv) on the optical front, most galaxies have elliptical morphologies (∼62%) while spirals form the second major category (∼17%) followed by distorted (∼12%) and lenticular (∼7%) morphologies; and (v) division between the FR I and the FR II sources in the radio–optical luminosity plane is blurred, in tune with recent studies.
Relativistic MR-MP Energy Levels for K-like Fe
Authors: Santana Juan A. , Ishikawa Yasuyuki , Beiersdorfer Peter
Published: March 2020

Relativistic Multi-Reference Møller-Plesset (MR-MP) many-body perturbation theory calculations are reported for the ground and excited states of Fe viii. Energies are provided for states coming from the configurations

(l = s, p, d, and f) with

, p ≤ 3, and q ≤ 1. The MR-MP results were compared with the recommended observed values in the CHIANTI-v8 database and with previous ab-initio calculations. The MR-MP calculations reproduce 90% of the available observed values within 3500 cm−1. The previous accurate ab-initio calculations reproduce only 50% of the observed values within 3500 cm−1. The electronic structure of Fe viii is very complex and our MR-MP results show that accurate calculations require the inclusion of not only 3s
2–3d
2, 3p
2–3d
2, and 3s3p–3d
2 promotions but also of all electron correlations via perturbation theory.