bluuebunny/crossref_metadata_2025_split huggingface dataset:
EMBEDDED CLUSTERS IN THE LARGE MAGELLANIC CLOUD USING THE VISTA MAGELLANIC CLOUDS SURVEY*
Authors: Romita Krista , Lada Elizabeth , Cioni Maria-Rosa 
Published: April 2016

ABSTRACT
We present initial results of the first large-scale survey of embedded star clusters in molecular clouds in the Large Magellanic Cloud (LMC) using near-infrared imaging from the Visible and Infrared Survey Telescope for Astronomy Magellanic Clouds Survey. We explored a ∼1.65 deg2 area of the LMC, which contains the well-known star-forming region 30 Doradus as well as ∼14% of the galaxy’s CO clouds, and identified 67 embedded cluster candidates, 45 of which are newly discovered as clusters. We have determined the sizes, luminosities, and masses for these embedded clusters, examined the star formation rates (SFRs) of their corresponding molecular clouds, and made a comparison between the LMC and the Milky Way. Our preliminary results indicate that embedded clusters in the LMC are generally larger, more luminous, and more massive than those in the local Milky Way. We also find that the surface densities of both embedded clusters and molecular clouds is ∼3 times higher than in our local environment, the embedded cluster mass surface density is ∼40 times higher, the SFR is ∼20 times higher, and the star formation efficiency is ∼10 times higher. Despite these differences, the SFRs of the LMC molecular clouds are consistent with the SFR scaling law presented in Lada et al. This consistency indicates that while the conditions of embedded cluster formation may vary between environments, the overall process within molecular clouds may be universal.
PRIMUS + DEEP2: CLUSTERING OF X-RAY, RADIO, AND IR-AGNs AT z ∼ 0.7
Authors: Mendez Alexander J. , Coil Alison L. , Aird James , Skibba Ramin A. , Diamond-Stanic Aleksandar M. , Moustakas John , Blanton Michael R. , Cool Richard J. , Eisenstein Daniel J. , Wong Kenneth C. , Zhu Guangtun 
Published: April 2016

ABSTRACT
We measure the clustering of X-ray, radio, and mid-IR-selected active galactic nuclei (AGNs) at

0.2
<
z
<
1.2

using multi-wavelength imaging and spectroscopic redshifts from the PRIMUS and DEEP2 redshift surveys, covering seven separate fields spanning ∼10. Using the cross-correlation of AGNs with dense galaxy samples, we measure the clustering scale length and slope, as well as the bias, of AGNs selected at different wavelengths. Similar to previous studies, we find that X-ray and radio AGNs are more clustered than mid-IR-selected AGNs. We further compare the clustering of each AGN sample with matched galaxy samples designed to have the same stellar mass, star-formation rate (SFR), and redshift distributions as the AGN host galaxies and find no significant differences between their clustering properties. The observed differences in the clustering of AGNs selected at different wavelengths can therefore be explained by the clustering differences of their host populations, which have different distributions in both stellar mass and SFR. Selection biases inherent in AGN selection therefore determine the clustering of observed AGN samples. We further find no significant difference between the clustering of obscured and unobscured AGNs, using IRAC or Wide-field Infrared Survey Explorer colors or X-ray hardness ratio.
DISCOVERY OF A SUPERCLUSTER AT z ∼ 0.91 AND TESTING THE ΛCDM COSMOLOGICAL MODEL
Authors: Kim Jae-Woo , Im Myungshin , Lee Seong-Kook , Edge Alastair C. , Hyun Minhee , Kim Dohyeong , Choi Changsu , Hong Jueun , Jeon Yiseul , Jun Hyunsung David , Karouzos Marios , Kim Duho , Kim Ji Hoon , Kim Yongjung , Park Won-Kee , Taak Yoon Chan , Yoon Yongmin 
Published: April 2016

ABSTRACT
The ΛCDM cosmological model successfully reproduces many aspects of the galaxy and structure formation of the universe. However, the growth of large-scale structures (LSSs) in the early universe is not well tested yet with observational data. Here, we have utilized wide and deep optical–near-infrared data in order to search for distant galaxy clusters and superclusters (0.8 < z < 1.2). From the spectroscopic observation with the Inamori Magellan Areal Camera and Spectrograph (IMACS) on the Magellan telescope, three massive clusters at z ∼ 0.91 are confirmed in the SSA22 field. Interestingly, all of them have similar redshifts within Δ z ∼ 0.01 with velocity dispersions ranging from 470 to 1300 km s−1. Moreover, as the maximum separation is ∼15 Mpc, they compose a supercluster at z ∼ 0.91, meaning that this is one of the most massive superclusters at this redshift to date. The galaxy density map implies that the confirmed clusters are embedded in a larger structure stretching over ∼100 Mpc. ΛCDM models predict about one supercluster like this in our surveyed volume, consistent with our finding so far. However, there are more supercluster candidates in this field, suggesting that additional studies are required to determine if the ΛCDM cosmological model can successfully reproduce the LSSs at high redshift.
AN EXTREMELY FAST HALO HOT SUBDWARF STAR IN A WIDE BINARY SYSTEM
Authors: Németh Péter , Ziegerer Eva , Irrgang Andreas , Geier Stephan , Fürst Felix , Kupfer Thomas , Heber Ulrich 
Published: April 2016

ABSTRACT
New spectroscopic observations of the halo hyper-velocity star candidate SDSS J121150.27+143716.2 (V = 17.92 mag) revealed a cool companion to the hot subdwarf primary. The components have a very similar radial velocity and their absolute luminosities are consistent with the same distance, confirming the physical nature of the binary, which is the first double-lined hyper-velocity candidate. Our spectral decomposition of the Keck/ESI spectrum provided an sdB+K3V pair, analogous to many long-period subdwarf binaries observed in the Galactic disk. We found the subdwarf atmospheric parameters:

T

eff

=
30

600
±
500

K,

log
g
=
5.57
±
0.06

cm s−2, and He abundance

log
(
n
He

/

n
H
)
=
−
3.0
±
0.2

. Oxygen is the most abundant metal in the hot subdwarf atmosphere, and Mg and Na lines are the most prominent spectral features of the cool companion, consistent with a metallicity of

[
Fe

/

H
]
=
−
1.3

. The non-detection of radial velocity variations suggest the orbital period to be a few hundred days, in agreement with similar binaries observed in the disk. Using the SDSS-III flux calibrated spectrum we measured the distance to the system

d
=
5.5
±
0.5

kpc

, which is consistent with ultraviolet, optical, and infrared photometric constraints derived from binary spectral energy distributions. Our kinematic study shows that the Galactic rest-frame velocity of the system is so high that an unbound orbit cannot be ruled out. On the other hand, a bound orbit requires a massive dark matter halo. We conclude that the binary either formed in the halo or was accreted from the tidal debris of a dwarf galaxy by the Milky Way.
HOW LYMAN ALPHA EMISSION DEPENDS ON GALAXY STELLAR MASS
Authors: Oyarzún Grecco A. , Blanc Guillermo A. , González Valentino , Mateo Mario , III John I. Bailey , Finkelstein Steven L. , Lira Paulina , Crane Jeffrey D. , Olszewski Edward W. 
Published: April 2016

ABSTRACT
In this work, we show how the stellar mass (M
*) of galaxies affects the 3 < z < 4.6 Lyα equivalent width (EW) distribution. To this end, we design a sample of 629 galaxies in the M
* range

from the 3D-HST/CANDELS survey. We perform spectroscopic observations of this sample using the Michigan/Magellan Fiber System, allowing us to measure Lyα fluxes and use 3D-HST/CANDELS ancillary data. In order to study the Lyα EW distribution dependence on M
*, we split the whole sample in three stellar mass bins. We find that, in all bins, the distribution is best represented by an exponential profile of the form

. Through a Bayesian analysis, we confirm that lower M
* galaxies have higher Lyα EWs. We also find that the fraction A of galaxies featuring emission and the e-folding scale W
0 of the distribution anti-correlate with M
*, recovering expressions of the forms

and

. These results are crucial for proper interpretation of Lyα emission trends reported in the literature that may be affected by strong M
* selection biases.
De l'icône à l'exemple historique : Le discours de commémoration de Jeanne d'Arc par Marine Le Pen
Authors: Sini Lorella 
Published: April 2016

Dans cette étude nous analysons comment la figure mythique de Jeanne d’Arc dans le discours de Marine Le Pen du 1er mai, s’actualise dans l’énonciation et le contexte politique particulier de l’année 2015, en exemple historique. L’évocation de la vie héroïque de la Pucelle d’Orléans est exploitée par la leader frontiste afin de construire un nouvel ethos. En s’identifiant à cette figure consensuelle, elle se pose en candidate crédible pour les futures présidentielles, et elle sert - tout en maintenant une posture « antisystème » - une opération de légitimation de son parti (la « dédiabolisation »).
Mediastinal pancreatic pseudocyst
Authors: Nasa Mukesh , Choudhary Narendra , Patil Gaurav , Puri Rajesh 
Published: April 2016

AbstractPancreatic pseudocyst is a well-known complication of both acute and chronic pancreatitis. It is a collection of fluid due to acute or chronic inflammation of pancreas or from injury. A pseudocyst with mediastinal extension is a rare entity. There are only few reports of endoscopic transesophageal drainage of mediastinal pseudocysts. We present a case of mediastinal pseudocyst in a 45-year-old male who presented with dysphagia, weight loss, fever, and productive cough which was managed endoscopically by endoscopic ultrasound-guided transesophageal aspiration.
Small neuroendocrine tumor of the duodenal bulb: Endoscopic submucosal dissection, laparoscopic and endoscopic cooperative surgery or surgery?
Authors: Chrysanthos Nikolaos V. , Anagnostopoulou Evagelia , Triga Eleni , Sakelariou Stratigoula , Korkolopoulou Pinelopi 
Published: April 2016

AbstractNeuroendocrine neoplasms of the gastric tube are less common than adenocarcinomas. Topography includes stomach, small intestine, Vater ampulla, and gross intestine. They are graded as neuroendocrine tumors grade I and II (NETs GI and GII) and neuroendocrine carcinomas GIII based on Ki-67 index and mitotic count.[1] Endoscopic treatment for GI NETs ≤1 cm that does not extend beyond the submucosal layer and does not demonstrate lymph node metastasis is recommended. Tumors ≥2 cm, with lymph node metastasis, are indicated for surgical treatment. The treatment strategy for tumors between 10 and 20 mm in size remains controversial.[2] We present a rare case of a 60-year-old male patient with end-stage renal failure who underwent a screening pretransplantation endoscopic control. Colonoscopy had no pathological findings. Gastroscopy reveals an abnormal mucosa in the anterior upper part of the duodenal bulb that was described as a micronodular mucosa and a central nodule of 6 mm with erythematous mucosa. Histology of the micronodular mucosa reveals a heterotopic gastric mucosa and a small hyperplastic polyp. Biopsies from the nodule reveal a carcinoid tumor (NET GI). Immunohistochemistry: Positive chromogranin levels, low mitotic index (1/10 HPF), and Ki-67 index <1% [Figure 2]. Gastrin levels were normal and chromogranin levels were abnormal (314 ng/ml, ULN <120 ng/ml). Spiral tomography of the thorax and the abdomen were normal. Endoscopic submucosal dissection is indicated for small NETs (≤1 cm). Laparoscopic and endoscopic cooperative surgery is a novel method, but the experience is limited. Surgery is the best choice for large NETs (>2 cm) and those of the duodenal bulb with histological extensions and the lack of assessing depth invasion.
Mercury dynamics and mass balance in a subtropical forest, southwestern China
Authors: Ma Ming , Wang Dingyong , Du Hongxia , Sun Tao , Zhao Zheng , Wang Yongmin , Wei Shiqiang 
Published: April 2016

Abstract. The mid-subtropical forest area in southwest China was affected by anthropogenic mercury (Hg) emissions over the past 3 decades. We quantified mercury dynamics on the forest field and measured fluxes and pools of Hg in litterfall, throughfall, stream water and forest soil in an evergreen broadleaved forest field in southwestern China. Total Hg (THg) input by the throughfall and litterfall was assessed at 32.2 and 42.9 µg m−2 yr−1, respectively, which was remarkably higher than those observed from other forest fields in the background of North America and Europe. Hg fluxes across the soil–air interface (18.6 mg m−2 yr−1) and runoff and/or stream flow (7.2 µg m−2 yr−1) were regarded as the dominant ways for THg export from the forest field. The forest field hosts an enormous amount of atmospheric Hg, and its reserves is estimated to be 25 341 µg m2. The ratio of output to input Hg fluxes (0.34) is higher compared with other study sites. The higher output / input ratio may represent an important ecological risk for the downstream aquatic ecosystems, even if the forest field could be an effective sink of Hg.
Studying the vertical aerosol extinction coefficient by comparing in situ airborne data and elastic backscatter lidar
Authors: Rosati Bernadette , Herrmann Erik , Bucci Silvia , Fierli Federico , Cairo Francesco , Gysel Martin , Tillmann Ralf , Größ Johannes , Gobbi Gian Paolo , Di Liberto Luca , Di Donfrancesco Guido , Wiedensohler Alfred , Weingartner Ernest , Virtanen Annele , Mentel Thomas F. , Baltensperger Urs 
Published: April 2016

Abstract. Vertical profiles of aerosol particle optical properties were explored in a case study near the San Pietro Capofiume (SPC) ground station during the PEGASOS Po Valley campaign in the summer of 2012. A Zeppelin NT airship was employed to investigate the effect of the dynamics of the planetary boundary layer at altitudes between ∼  50 and 800 m above ground. Determined properties included the aerosol particle size distribution, the hygroscopic growth factor, the effective index of refraction and the light absorption coefficient. The first three parameters were used to retrieve the light scattering coefficient. Simultaneously, direct measurements of both the scattering and absorption coefficient were carried out at the SPC ground station. Additionally, a single wavelength polarization diversity elastic lidar system provided estimates of aerosol extinction coefficients using the Klett method to accomplish the inversion of the signal, for a vertically resolved comparison between in situ and remote-sensing results. Note, however, that the comparison was for the most part done in the altitude range where the overlap function is incomplete and accordingly uncertainties are larger. First, the airborne results at low altitudes were validated with the ground measurements. Agreement within approximately ±25 and ±20 % was found for the dry scattering and absorption coefficient, respectively. The single scattering albedo, ranged between 0.83 and 0.95, indicating the importance of the absorbing particles in the Po Valley region. A clear layering of the atmosphere was observed during the beginning of the flight (until ∼  10:00 LT – local time) before the mixing layer (ML) was fully developed. Highest extinction coefficients were found at low altitudes, in the new ML, while values in the residual layer, which could be probed at the beginning of the flight at elevated altitudes, were lower. At the end of the flight (after ∼  12:00 LT) the ML was fully developed, resulting in constant extinction coefficients at all altitudes measured on the Zeppelin NT. Lidar estimates captured these dynamic features well and good agreement was found for the extinction coefficients compared to the in situ results, using fixed lidar ratios (LR) between 30 and 70 sr for the altitudes probed with the Zeppelin. These LR are consistent with values for continental aerosol particles that can be expected in this region.
Vortex-wide chlorine activation by a mesoscale PSC event in the Arctic winter of 2009/10
Authors: Wegner Tobias , Pitts Michael C. , Poole Lamont R. , Tritscher Ines , Grooß Jens-Uwe , Nakajima Hideaki 
Published: April 2016

Abstract. In the Arctic polar vortex of the 2009/10 winter temperatures were low enough to allow widespread formation of polar stratospheric clouds (PSCs). These clouds occurred during the initial chlorine activation phase which provided the opportunity to investigate the impact of PSCs on chlorine activation. Satellite observations of gas-phase species and PSCs are used in combination with trajectory modeling to assess this initial activation. The initial activation occurred in association with the formation of PSCs over the east coast of Greenland at the beginning of January 2010. Although this area of PSCs covered only a small portion of the vortex, it was responsible for almost the entire initial activation of chlorine vortex wide. Observations show HCl (hydrochloric acid) mixing ratios decreased rapidly in and downstream of this region. Trajectory calculations and simplified heterogeneous chemistry modeling confirmed that the initial chlorine activation continued until ClONO2 (chlorine nitrate) was completely depleted and the activated air masses were advected throughout the polar vortex. For the calculation of heterogeneous reaction rates, surface area density is estimated from backscatter observations. Modeled heterogeneous reaction rates along trajectories intersecting with the PSCs indicate that the initial phase of chlorine activation occurred in just a few hours. These calculations also indicate that chlorine activation on the binary background aerosol is significantly slower than on the PSC particles and the observed chlorine activation can only be explained by an increase in surface area density due to PSC formation. Furthermore, there is a strong correlation between the magnitude of the observed HCl depletion and PSC surface area density.
Organic and inorganic decomposition products from the thermal desorption of atmospheric particles
Authors: Williams Brent J. , Zhang Yaping , Zuo Xiaochen , Martinez Raul E. , Walker Michael J. , Kreisberg Nathan M. , Goldstein Allen H. , Docherty Kenneth S. , Jimenez Jose L. 
Published: April 2016

Abstract. Atmospheric aerosol composition is often analyzed using thermal desorption techniques to evaporate samples and deliver organic or inorganic molecules to various designs of detectors for identification and quantification. The organic aerosol (OA) fraction is composed of thousands of individual compounds, some with nitrogen- and sulfur-containing functionality and, often contains oligomeric material, much of which may be susceptible to decomposition upon heating. Here we analyze thermal decomposition products as measured by a thermal desorption aerosol gas chromatograph (TAG) capable of separating thermal decomposition products from thermally stable molecules. The TAG impacts particles onto a collection and thermal desorption (CTD) cell, and upon completion of sample collection, heats and transfers the sample in a helium flow up to 310 °C. Desorbed molecules are refocused at the head of a gas chromatography column that is held at 45 °C and any volatile decomposition products pass directly through the column and into an electron impact quadrupole mass spectrometer. Analysis of the sample introduction (thermal decomposition) period reveals contributions of NO+ (m/z 30), NO2+ (m/z 46), SO+ (m/z 48), and SO2+ (m/z 64), derived from either inorganic or organic particle-phase nitrate and sulfate. CO2+ (m/z 44) makes up a major component of the decomposition signal, along with smaller contributions from other organic components that vary with the type of aerosol contributing to the signal (e.g., m/z 53, 82 observed here for isoprene-derived secondary OA). All of these ions are important for ambient aerosol analyzed with the aerosol mass spectrometer (AMS), suggesting similarity of the thermal desorption processes in both instruments. Ambient observations of these decomposition products compared to organic, nitrate, and sulfate mass concentrations measured by an AMS reveal good correlation, with improved correlations for OA when compared to the AMS oxygenated OA (OOA) component. TAG signal found in the traditional compound elution time period reveals higher correlations with AMS hydrocarbon-like OA (HOA) combined with the fraction of OOA that is less oxygenated. Potential to quantify nitrate and sulfate aerosol mass concentrations using the TAG system is explored through analysis of ammonium sulfate and ammonium nitrate standards. While chemical standards display a linear response in the TAG system, redesorptions of the CTD cell following ambient sample analysis show some signal carryover on sulfate and organics, and new desorption methods should be developed to improve throughput. Future standards should be composed of complex organic/inorganic mixtures, similar to what is found in the atmosphere, and perhaps will more accurately account for any aerosol mixture effects on compositional quantification.
Lidar arc scan uncertainty reduction through scanning geometry optimization
Authors: Wang Hui , Barthelmie Rebecca J. , Pryor Sara C. , Brown Gareth. 
Published: April 2016

Abstract. Doppler lidars are frequently operated in a mode referred to as arc scans, wherein the lidar beam scans across a sector with a fixed elevation angle and the resulting measurements are used to derive an estimate of the n minute horizontal mean wind velocity (speed and direction). Previous studies have shown that the uncertainty in the measured wind speed originates from turbulent wind fluctuations and depends on the scan geometry (the arc span and the arc orientation). This paper is designed to provide guidance on optimal scan geometries for two key applications in the wind energy industry: wind turbine power performance analysis and annual energy production prediction. We present a quantitative analysis of the retrieved wind speed uncertainty derived using a theoretical model with the assumption of isotropic and frozen turbulence, and observations from three sites that are onshore with flat terrain, onshore with complex terrain and offshore, respectively. The results from both the theoretical model and observations show that the uncertainty is scaled with the turbulence intensity such that the relative standard error on the 10 min mean wind speed is about 30 % of the turbulence intensity. The uncertainty in both retrieved wind speeds and derived wind energy production estimates can be reduced by aligning lidar beams with the dominant wind direction, increasing the arc span and lowering the number of beams per arc scan. Large arc spans should be used at sites with high turbulence intensity and/or large wind direction variation.