bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ca ii TRIPLET SPECTROSCOPY OF SMALL MAGELLANIC CLOUD RED GIANTS. IV. ABUNDANCES FOR A LARGE SAMPLE OF FIELD STARS AND COMPARISON WITH THE CLUSTER SAMPLE
Authors: Parisi M. C. , Geisler D. , Carraro G. , Clariá J. J. , Villanova S. , Gramajo L. V. , Sarajedini A. , Grocholski A. J. 
Published: June 2019

ABSTRACT
This paper represents a major step forward in the systematic and homogeneous study of Small Magellanic Cloud (SMC) star clusters and field stars carried out by applying the calcium triplet technique. We present in this work the radial velocity and metallicity of approximately 400 red giant stars in 15 SMC fields, with typical errors of about 7 km s−1 and 0.16 dex, respectively. We added to this information our previously determined metallicity values for 29 clusters and approximately 350 field stars using the identical techniques. Using this enlarged sample, we analyze the metallicity distribution and gradient in this galaxy. We also compare the chemical properties of the clusters and of their surrounding fields. We find a number of surprising results. While the clusters, taken as a whole, show no strong evidence for a metallicity gradient (MG), the field stars exhibit a clear negative gradient in the inner region of the SMC, consistent with the recent results of Dobbie et al. For distances to the center of the galaxy less than 4°, field stars show a considerably smaller metallicity dispersion than that of the clusters. However, in the external SMC regions, clusters and field stars exhibit similar metallicity dispersions. Moreover, in the inner region of the SMC, clusters appear to be concentrated in two groups: one more metal-poor and another more metal-rich than field stars. Individually considered, neither cluster group presents an MG. Most surprisingly, the MG for both stellar populations (clusters and field stars) appears to reverse sign in the outer regions of the SMC. The difference between the cluster metallicity and the mean metallicity of the surrounding field stars turns out to be a strong function of the cluster metallicity. These results could be indicating different chemical evolution histories for these two SMC stellar populations. They could also indicate variations in the chemical behavior of the SMC in its internal and external regions.
EVIDENCE FOR FLUORESCENT Fe ii EMISSION FROM EXTENDED LOW IONIZATION OUTFLOWS IN OBSCURED QUASARS
Authors: Wang Tinggui , Ferland Gary J. , Yang Chenwei , Wang Huiyuan , Zhang Shaohua 
Published: June 2019

ABSTRACT
Recent studies have shown that outflows in at least some broad absorption line (BAL) quasars are extended well beyond the putative dusty torus. Such outflows should be detectable in obscured quasars. We present four WISE selected infrared red quasars with very strong and peculiar ultraviolet Fe ii emission lines: strong UV Fe ii UV arising from transitions to ground/low excitation levels, and very weak Fe ii at wavelengths longer than 2800 Å. The spectra of these quasars display strong resonant emission lines, such as C iv, Al iii and Mg ii but sometimes, a lack of non-resonant lines such as C iii], S iii and He ii. We interpret the Fe ii lines as resonantly scattered light from the extended outflows that are viewed nearly edge-on, so that the accretion disk and broad line region are obscured by the dusty torus, while the extended outflows are not. We show that dust free gas exposed to strong radiation longward of 912 Å produces Fe ii emission very similar to that observed. The gas is too cool to collisionally excite Fe ii lines, accounting for the lack of optical emission. The spectral energy distribution from the UV to the mid-infrared can be modeled as emission from a clumpy dusty torus, with UV emission being reflected/scattered light either by the dusty torus or the outflow. Within this scenario, we estimate a minimum covering factor of the outflows from a few to 20% for the Fe ii scattering region, suggesting that Fe ii BAL quasars are at a special stage of quasar evolution.
PROPERTIES OF INTERSTELLAR MEDIUM IN INFRARED-BRIGHT QSOs PROBED BY [O i] 63 μm AND [C ii] 158 μm EMISSION LINES*
Authors: Zhao(赵应和) Yinghe , Yan Lin , Tsai Chao-Wei 
Published: June 2019

ABSTRACT
We present a study of the interstellar medium (ISM) in the host galaxies of nine QSOs at 0.1 < z < 0.2 with black hole masses of

to

based on the far-IR spectroscopy taken with Herschel Space Observatory. We detect the [O i] 63 μm ([C ii] 158 μm) emission in 6 (8) out of 8 (9) sources. Our QSO sample has far-infrared luminosities (

) ∼ several times

. The observed line-to-

ratios (

/

and

/

) are in the ranges of 2.6 × 10−4 to 10−2 and 2.8 × 10−4 to 2 × 10−3, respectively (including upper limits). These ratios are comparable to the values found in local ULIRGs, but higher than the average value published so far for

IR-bright QSOs. One target, W0752+19, shows an additional broad velocity component (∼720 km s−1) and exceptionally strong [O i] 63 μm emission with

/

of 10−2, an order of magnitude higher than the average value found among local (U)LIRGs. Combining with the analyses of the Sloan Digital Sky Survey optical spectra, we conclude that the [O i] 63 μm emission in these QSOs is unlikely excited by shocks. We infer that the broad [O i] 63 μm emission in W0752+19 could arise from the warm and dense ISM in the narrow-line region of the central active galactic nucleus. Another possible explanation is the existence of a dense gas outflow with

cm−3, where the corresponding broad [C ii] emission is suppressed. Based on the far-IR [O i] and [C ii] line ratios, we estimate constraints on the ISM density and UV radiation field intensity of

cm−3 and

, respectively. These values are consistent with those found in local Seyfert 1 ULIRGs. In contrast, the gas with broad velocity width in W0752+19 has

cm−3 and

.
HIGH SPATIAL RESOLUTION Fe xii OBSERVATIONS OF SOLAR ACTIVE REGIONS
Authors: Testa Paola , Pontieu Bart De , Hansteen Viggo 
Published: June 2019

ABSTRACT
We use UV spectral observations of active regions with the Interface Region Imaging Spectrograph (IRIS) to investigate the properties of the coronal Fe xii 1349.4 Å emission at unprecedented high spatial resolution (∼0.33″). We find that by using appropriate observational strategies (i.e., long exposures, lossless compression), Fe xii emission can be studied with IRIS at high spatial and spectral resolution, at least for high-density plasma (e.g., post-flare loops and active region moss). We find that upper transition region (TR; moss) Fe xii emission shows very small average Doppler redshifts (

∼ 3 km s−1) as well as modest non-thermal velocities (with an average of ∼24 km s−1 and the peak of the distribution at ∼15 km s−1). The observed distribution of Doppler shifts appears to be compatible with advanced three-dimensional radiative MHD simulations in which impulsive heating is concentrated at the TR footpoints of a hot corona. While the non-thermal broadening of Fe xii 1349.4 Å peaks at similar values as lower resolution simultaneous Hinode Extreme Ultraviolet Imaging Spectrometer (EIS) measurements of Fe xii 195 Å, IRIS observations show a previously undetected tail of increased non-thermal broadening that might be suggestive of the presence of subarcsecond heating events. We find that IRIS and EIS non-thermal line broadening measurements are affected by instrumental effects that can only be removed through careful analysis. Our results also reveal an unexplained discrepancy between observed 195.1/1349.4 Å Fe xii intensity ratios and those predicted by the CHIANTI atomic database.
DISTRIBUTION OF COLD (≲300 K) ATOMIC GAS IN GALAXIES: RESULTS FROM THE GBT H i ABSORPTION SURVEY PROBING THE INNER HALOS (ρ < 20 kpc) OF LOW-z GALAXIES∗
Authors: Borthakur Sanchayeeta 
Published: June 2019

ABSTRACT
We present the Green Bank Telescope absorption survey of cold atomic hydrogen (≲300 K) in the inner halo of low-redshift galaxies. The survey aims to characterize the cold gas distribution and to address where the condensation—the process where ionized gas accreted by galaxies condenses into cold gas within the disks of galaxies—occurs. Our sample consists of 16 galaxy–quasar pairs with impact parameters of ≤20 kpc. We detected an H i absorber associated with J0958+3222 (NGC 3067) and H i emission from six galaxies. We also found two Ca ii absorption systems in the archival SDSS data associated with galaxies J0958+3222 and J1228+3706. Our detection rate of H i absorbers with optical depths of ≥0.06 is ∼7%. We also find that the cold H i phase (≲300 K) is 44(±18)% of the total atomic gas in the sightline probing J0958+3222. We find no correlation between the peak optical depth and impact parameter or stellar and H i radii normalized impact parameters, ρ/R
90 and ρ/R
H i
. We conclude that the process of condensation of inflowing gas into cold (≲300 K) H i occurs at the ρ ≪ 20 kpc. However, the warmer phase of neutral gas (T ∼ 1000 K) can exist out to much larger distances, as seen in emission maps. Therefore, the process of condensation of warm to cold H i is likely occurring in stages from ionized to warm H i in the inner halo and then to cold H i very close to the galaxy disk.
NUMERICAL SIMULATION OF THE SVS 13 MICROJET AND BOW SHOCK BUBBLE
Authors: Gardner Carl L. , Jones Jeremiah R. , Hodapp Klaus W. 
Published: June 2019

ABSTRACT
Numerical simulations of the SVS 13 microjet and bow shock bubble are performed using the WENO method that reproduces the main features and dynamics of data from the Keck Telescope/OSIRIS velocity-resolved integral field spectrograph: an expanding, cooler bow shock bubble, with the bubble center moving at approximately 50 km s−1 with a radial expansion velocity of 11 km s−1, surrounding the fast, hotter jet, which is propagating at 156 km s−1. Contact and bow shock waves are visible in the simulations both from the initial short jet pulse that creates the nearly spherical bow shock bubble and from the fast microjet, while a terminal Mach disk shock is visible near the tip of the continuous microjet, which reduces the velocity of the jet gas down to the flow velocity of the contact discontinuity at the leading edge of the jet. At 21.1 years after the launch of the initial bubble pulse, the jet has caught up with and penetrated almost all the way across the bow shock bubble of the slower initial pulse. At times later than about 22 years, the jet has penetrated through the bubble and thereafter begins to subsume its spherical form. Emission maps from the simulations of the jet—traced by the emission of the shock-excited 1.644 μm [Fe ii] line—and the bow shock bubble—traced in the lower excitation 2.122 μm H2 1–0 S(1) line—projected onto the plane of the sky are presented, and are in good agreement with the Keck observations.
EXPONENTIAL DISKS FROM STELLAR SCATTERING. III. STOCHASTIC MODELS
Authors: Elmegreen Bruce G. , Struck Curtis 
Published: June 2019

ABSTRACT
Stellar scattering off irregularities in a galaxy disk has been shown to make an exponential radial profile, but no fundamental reason for this has been suggested. Here, we show that exponentials are mathematically expected from random scattering in a disk when there is a slight inward bias in the scattering probability. Such a bias was present in our previous scattering experiments that formed exponential profiles. Double exponentials can arise when the bias varies with radius. This is a fundamental property of scattering and may explain why piece-wise exponential profiles are ubiquitous in galaxies, even after minor mergers and other disruptive events.
Observing Isotopologue Bands in Terrestrial Exoplanet Atmospheres with the James Webb Space Telescope: Implications for Identifying Past Atmospheric and Ocean Loss
Authors: Lincowski Andrew P. , Lustig-Yaeger Jacob , Meadows Victoria S. 
Published: June 2019

Abstract
Terrestrial planets orbiting M dwarfs may soon be observed with the James Webb Space Telescope (JWST) to characterize their atmospheric composition and search for signs of habitability or life. These planets may undergo significant atmospheric and ocean loss due to the superluminous pre-main-sequence phase of their host stars, which may leave behind abiotically generated oxygen, a false positive for the detection of life. Determining if ocean loss has occurred will help assess potential habitability and whether or not any O2 detected is biogenic. In the solar system, differences in isotopic abundances have been used to infer the history of ocean loss and atmospheric escape (e.g., Venus, Mars). We find that isotopologue measurements using transit transmission spectra of terrestrial planets around late-type M dwarfs like TRAPPIST-1 may be possible with JWST, if the escape mechanisms and resulting isotopic fractionation were similar to Venus. We present analyses of post-ocean-loss O2- and CO2-dominated atmospheres containing a range of trace gas abundances. Isotopologue bands are likely detectable throughout the near-infrared (1–8 μm), especially 3–4 μm, although not in CO2-dominated atmospheres. For Venus-like D/H ratios 100 times that of Earth, TRAPPIST-1b transit signals of up to 79 ppm are possible by observing HDO. Similarly, 18O/16O ratios 100 times that of Earth produce signals at up to 94 ppm. Detection at signal-to-noise ratio = 5 may be attained on these bands with as few as four to 11 transits, with optimal use of JWST’s NIRSpec Prism. Consequently, H2O and CO2 isotopologues could be considered as indicators of past ocean loss and atmospheric escape for JWST observations of terrestrial planets around M dwarfs.
Gas and Dust Properties in the Chamaeleon Molecular Cloud Complex Based on the Optically Thick H i
Authors: Hayashi Katsuhiro , Okamoto Ryuji , Yamamoto Hiroaki , Hayakawa Takahiro , Tachihara Kengo , Fukui Yasuo 
Published: June 2019

Abstract
Gas and dust properties in the Chamaeleon molecular cloud complex have been investigated with emission lines from the atomic hydrogen (H i) and 12CO molecules, dust optical depth at 353 GHz (τ
353), and J-band infrared extinction (A

J
). We have found a scatter correlation between the H i integrated intensity (W
H i
) and τ
353 in the Chamaeleon region. The scattering has been examined in terms of a possible large optical depth in H i emission (τ
H i
) using a total column density (N
H) model based on τ
353. A nonlinear relation of τ
353 with the ∼1.2 power of A

J
has been found in opaque regions (A

J
≳ 0.3 mag), which may indicate a dust evolution effect. If we apply this nonlinear relation to the N
H model (i.e., N
H ∝

τ

353

1

/

1.2

) allowing arbitrary τ
H i
, the model curve reproduces well the W
H i
–τ
353 scatter correlation, suggesting optically thick H i (τ
H i
∼ 1.3) extended around the molecular clouds. Based on the correlations between the CO integrated intensity and the N
H model, we have derived the CO-to-H2 conversion factor (X
CO) on ∼1.°5 scales (corresponding to ∼4 pc) and found spatial variations of X
CO ∼ (0.5–3) × 1020 cm−2 K−1 km−1 s across the cloud complex, possibly depending on the radiation field inside or surrounding the molecular clouds. These gas properties found in the Chamaeleon region are discussed through a comparison with other local molecular cloud complexes.
Spatially Resolved Stellar Populations and Kinematics with KCWI: Probing the Assembly History of the Massive Early-type Galaxy NGC 1407
Authors: Ferré-Mateu Anna , Forbes Duncan A. , McDermid Richard M. , Romanowsky Aaron J. , Brodie Jean P. 
Published: June 2019

Abstract
Using the newly commissioned Keck Cosmic Web Imager (KCWI) instrument on the Keck II telescope, we analyze the stellar kinematics and stellar populations of the well-studied massive early-type galaxy (ETG) NGC 1407. We obtained high signal-to-noise integral field spectra for a central and an outer (around one effective radius toward the southeast direction) pointing with integration times of just 600 s and 2400 s, respectively. We confirm the presence of a kinematically distinct core also revealed by VLT/MUSE data of the central regions. While NGC 1407 was previously found to have stellar populations characteristic of massive ETGs (with radially constant old ages and high alpha-enhancements), it was claimed to show peculiar supersolar metallicity peaks at a large radius that deviated from an otherwise strong negative metallicity gradient, which is hard to reconcile within a “two-phase” formation scenario. Our outer pointing confirms the near-uniform old ages and the presence of a steep metallicity gradient, but with no evidence for anomalously high metallicity values at large galactocentric radii. We find a rising outer velocity dispersion profile and high values of the fourth-order kinematic moment—an indicator of possible anisotropy. This coincides with the reported transition from a bottom-heavy to a Salpeter initial mass function, which may indicate that we are probing the transition region from the “in situ” to the accreted phase. With short exposures, we have been able to derive robust stellar kinematics and stellar populations in NGC 1407 to ∼1 effective radius. This experiment shows that future work with KCWI will enable 2D kinematics and stellar populations to be probed within the low surface brightness regions of galaxy halos in an effective way.
Automatizing the Detection of Erroneous Species Occurrence Records
Authors: Jimenez Rosenberg Raul , Sierra-Alcocer Raul 
Published: June 2019

The work involved in checking millions of records by hand is hard and requires thousands of human hours. At the increasing rate at which we are collecting new data from different sources with a wide range of 'quality', the problem is getting worse. An institution like CONABIO (National Commission for the Knowledge and Use of Biodiversity, Mexico) dedicates a large amount of human resources to review species records to ensure that data published by the institution has high quality. At CONABIO we are designing a system to help us direct our attention to the most problematic data.
Our methodology (Stephens et al. 2019) scores a species record according to the features of its location, and it labels it as suspicious if it has a low score. A low score means that the features of the location are unusual for that species. The features of locations are the set of abiotic, like climate and topographic charactersitics and occurrences of other species in the location. Although this does not mean that a record is wrong, it may be an indicator that a record needs to be assessed.
The system we are designing works in two scenarios: in one, it scores new data based on parameters adjusted from validated data; in the second, the system checks for consistency in the database, that is, it flags records of a species that seem like outliers according to the predominant records distribution for that species. Our initial tests show that we could speed up the detection process for some problematic records. In one of our tests, where we used data that were previously labeled by hand, the method flagged 624 records, out of which 70 were confirmed as incorrect data. If we look only at the precision of the results it might seem like a poor performance, however if we look at the amount of work it might save us, it looks promising because to find the same number of inaccurate records without any assistance we would have had to review almost 5,000 records.
This talk is a proof of concept for this system, and details on our initial results, reviewing both weaknesses and strengths.
Biodiversity Information for Development: Building a global community of practice to mobilize and use biodiversity data
Authors: Raymond Mélianie , Rodrigues Andrew , Russell Laura Anne 
Published: June 2019

Biodiversity Information for Development, or BID, is a programme funded by the European Union and led by the Global Biodiversity Information Facility (GBIF), aiming to increase the amount of biodiversity information available for use in scientific research and policymaking. In its first phase, BID provided funding to 61 projects in the nations of sub-Saharan Africa, the Caribbean and the Pacific between 2015-2019, with a strong focus on developing capacity to mobilize, manage and use biodiversity data within the project teams and their institutions, and through the establishment and strengthening of national nodes.
The capacity development approach centred on establishing a community of practice to bring in the expertise in the broader GBIF network to support the project teams in meeting their goals. This involved designing curricula for two workshops in the areas of data mobilization and data use for decision making; developing activities and materials to strengthen a base of mentors and trainers; establishing technical helpdesk support; and matchmaking to provide mentoring support to the funded projects. The community of practice, through mentoring and reuse of the workshop materials, has been expanded to support the capacity development needs in other programmes, reaching other regions, including Asia, South-East Europe and Eurasia.
During this presentation, we will review the main findings of the BID impact study and guiding examples from within the BID programme to identify the key successes and lessons learned relating to capacity development. As this approach has wider application to the biodiversity community, we invite discussion how we can build on the experience through the BID programme to further develop our community of practice, narrowing knowledge gaps between various groups of biodiversity professionals.
How Artificial Intelligence and Machine Learning can Assist in Collections Curation
Authors: Checksfield Simon 
Published: June 2019

With increasing pressure on the limited taxonomical expertise in not only Commonwealth Scientific and Industry Research Organisation (CSIRO) but the world, new and innovative ways need to be found to assist in the curation and identification of biological specimens.
CSIRO, through the National Research Collections Australia (NRCA) and Data 61 is hoping to begin a new program of work focused on using Artificial Intelligence (AI) and Machine Learning to build a framework and tools that can help identify a specimen from an image. The framework will include AI models that have been trained by expert taxonomists, thus providing a level of accuracy that has some intrinsic value.
NRCA is also exploring how AI could be linked or cross referenced with another initiative using rapid genetic barcoding to identify all newly collected specimens. Combining genetic and AI determinations will add weight to each, and potentially expose some new AI challenges, such as identifying morphological elements against genomic elements.
Whilst acknowledging challenges still exist regarding standards, acceptance of identification, provenance, accuracy and governance, the NRCA is hoping AI can assist in freeing the time of our researchers and technicians to work on more pressing and complex issues by reducing their time spent on basic identification.
The impact of such a program will also reach into industry and the general public through tools based on the AI models. There is also an opportunity to use this initiative to create global centers of taxonomic expertise, which anyone can use to help identify a specimen.