scholarly journals A Census of the Stellar Populations in the Sco-Cen Complex*

2021 ◽  
Vol 163 (1) ◽  
pp. 24
Author(s):  
K. L. Luhman
Keyword(s):  
High Precision ◽  
Stellar Populations ◽  
Young Stars ◽  
Initial Mass ◽  
Wide Field ◽  
The Third ◽  
Sky Survey ◽  
Data Release ◽  
Mass Functions ◽  
Infrared Survey

Abstract I have used high-precision photometry and astrometry from the early installment of the third data release of Gaia (EDR3) to perform a survey for members of the stellar populations within the Sco-Cen complex, which consist of Upper Sco, UCL/LCC, the V1062 Sco group, Ophiuchus, and Lupus. Among Gaia sources with σ π < 1 mas, I have identified 10,509 candidate members of those populations. I have compiled previous measurements of spectral types, Li equivalent widths, and radial velocities for the candidates, which are available for 3169, 1420, and 1740 objects, respectively. In a subset of candidates selected to minimize field star contamination, I estimate that the contamination is ≲1% and the completeness is ∼90% at spectral types of ≲M6–M7 for the populations with low extinction (Upper Sco, V1062 Sco, UCL/LCC). I have used that cleaner sample to characterize the stellar populations in Sco-Cen in terms of their initial mass functions, ages, and space velocities. For instance, all of the populations in Sco-Cen have histograms of spectral types that peak near M4–M5, which indicates that they share similar characteristic masses for their initial mass functions (∼0.15–0.2 M ⊙). After accounting for incompleteness, I estimate that the Sco-Cen complex contains nearly 10,000 members with masses above ∼0.01 M ⊙. Finally, I also present new estimates for the intrinsic colors of young stars and brown dwarfs (≲20 Myr) in bands from Gaia EDR3, the Two Micron All Sky Survey, the Wide-field Infrared Survey Explorer, and the Spitzer Space Telescope.

scholarly journals Transformations from WISE to 2MASS, SDSS and BVI Photometric Systems: II. Transformation Equations for Red-Clump Stars

2012 ◽  
Vol 29 (2) ◽  
pp. 121-131 ◽  
Author(s):  
S. Bilir ◽  
S. Karaali ◽  
N. D. Dağtekin ◽  
Ö. Önal ◽  
S. Ak ◽  
...  
Keyword(s):  
Field Survey ◽  
Sloan Digital Sky Survey ◽  
Wide Field ◽  
Experiment Data ◽  
The Third ◽  
Final Sample ◽  
Sky Survey ◽  
Data Release ◽  
Red Clump ◽  
Absolute Magnitudes

AbstractWe present colour transformations for the conversion of Wide-Field Survey Explorer W1, W2, and W3 magnitudes to the Johnson–Cousins BVIc, Sloan Digital Sky Survey gri, and Two Micron All Sky Survey JHKs photometric systems, for red clump (RC) stars. RC stars were selected from the Third Radial Velocity Experiment Data Release. The apparent magnitudes were collected by matching the coordinates of this sample with different photometric catalogues. The final sample (355 RC stars) was used to obtain metallicitydependent and free-of-metallicity transformations. These transformations combined with known absolute magnitudes at shorter wavelengths can be used in space density determinations for the Galactic (thin and thick) discs at distances larger than the ones evaluated with JHKs photometry alone, hence providing a powerful tool in the analysis of Galactic structure.

scholarly journals H i galaxies with little star formation: an abundance of LIERs

2019 ◽  
Vol 485 (3) ◽  
pp. 3169-3184 ◽  
Author(s):  
Vaishali Parkash ◽  
Michael J I Brown ◽  
T H Jarrett ◽  
A Fraser-McKelvie ◽  
M E Cluver
Keyword(s):  
Star Formation ◽  
Emission Line ◽  
Central Star ◽  
Wide Field ◽  
Dark Energy Survey ◽  
Sky Survey ◽  
Low Levels ◽  
Field Unit ◽  
Energy Survey ◽  
Infrared Survey

Abstract We present a sample of 91 H i galaxies with little or no star formation, and discuss the analysis of the integral field unit (IFU) spectra of 28 of these galaxies. We identified H i galaxies from the H i Parkes All-Sky Survey Catalog (HICAT) with Wide-field Infrared Survey Explorer (WISE) colours consistent with low specific star formation (&lt;10−10.4 yr−1), and obtained optical IFU spectra with the Wide-Field Spectrograph (WiFeS). Visual inspection of the PanSTARRS, Dark Energy Survey, and Carnegie-Irvine imaging of 62 galaxies reveals that at least 32 galaxies in the sample have low levels of star formation, primarily in arms/rings. New IFU spectra of 28 of these galaxies reveals 3 galaxies with central star formation, 1 galaxy with low-ionization nuclear emission-line regions (LINERs), 20 with extended low-ionization emission-line regions (LIERs), and 4 with high excitation Seyfert (Sy) emission. From the spectroscopic analysis of H i selected galaxies with little star formation, we conclude that 75 per cent of this population are LINERs/LIERs.

scholarly journals Evidence of AGN-driven Outflows in Young Radio Quasars Selected from the Wide-field Infrared Survey Explorer

2013 ◽  
Vol 9 (S304) ◽  
pp. 347-348
Author(s):  
Minjin Kim ◽  
Luis C. Ho ◽  
Carol J. Lonsdale ◽  
Mark Lacy ◽  
Andrew W. Blain ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Near Infrared ◽  
Galactic Nuclei ◽  
Emission Lines ◽  
Wide Field ◽  
Near Infrared Spectra ◽  
Sky Survey ◽  
Line Widths ◽  
Infrared Survey ◽  
Narrow Emission

AbstractWe present near-infrared spectra of young radio quasars selected by cross-correlating the Wide-field Infrared Survey Explorer (WISE) all-sky survey catalog with the radio catalog [Faint Images of the Radio Sky at Twenty cm (FIRST) and NRAO VLA Sky Survey (NVSS)]. The objects have typical redshifts of z ≈ 2 and [O III] luminosities of 107 erg s−1 comparable to those of luminous quasars. The observed flux ratios of narrow emission lines indicate that these objects appear to be powered by active galactic nuclei. The [O III] line is broad, with full width at half maximum ~1300 to 2100 km s−1, significantly larger than that of ordinary quasars. These large line widths might be explained by jet-induced outflows.

scholarly journals The Third Data Release of the Beijing–Arizona Sky Survey

2019 ◽  
Vol 245 (1) ◽  
pp. 4 ◽  
Author(s):  
Hu Zou ◽  
Xu Zhou ◽  
Xiaohui Fan ◽  
Tianmeng Zhang ◽  
Zhimin Zhou ◽  
...  
Keyword(s):  
The Third ◽  
Sky Survey ◽  
Data Release

scholarly journals THE SLOAN DIGITAL SKY SURVEY QUASAR LENS SEARCH. III. CONSTRAINTS ON DARK ENERGY FROM THE THIRD DATA RELEASE QUASAR LENS CATALOG

2008 ◽  
Vol 135 (2) ◽  
pp. 512-519 ◽  
Author(s):  
Masamune Oguri ◽  
Naohisa Inada ◽  
Michael A. Strauss ◽  
Christopher S. Kochanek ◽  
Gordon T. Richards ◽  
...  
Keyword(s):  
Dark Energy ◽  
Sloan Digital Sky Survey ◽  
The Third ◽  
Sky Survey ◽  
Data Release

scholarly journals Synergy of wide-field infrared survey explorer (WISE) and the Sloan Digital Sky Survey in Stripe 82

2018 ◽  
Author(s):  
◽  
Marat Musin
Keyword(s):  
Stellar Mass ◽  
Sloan Digital Sky Survey ◽  
High Mass ◽  
Optical Data ◽  
Wide Field ◽  
Resolution Image ◽  
Sky Survey ◽  
Template Fitting ◽  
Very High ◽  
Infrared Survey

In this dissertation, I aim to study the evolution of galaxies over the last 6 Gyr by measuring the growth of the global stellar mass density (GSMD) since z = 0.8. My work combines the datasets from two very large surveys, namely, the optical data from the Sloan Digital Sky Survey (SDSS) Stripe 82 and the infrared data from the Wide-field Infrared Survey Explorer (WISE), and constructs a unique catalog of galaxies that have their spectral energy distributions (SEDs) measured consistently from 0.3 to 5 [mu]m in seven bands. This catalog, the largest of its kind, contains 9 million galaxies in [about] 300 deg[2] , will have a wide range of applications beyond the scope of this thesis. Extending galaxy SED measurements to restframe near-IR has two significant advantages: (1) dust extinction can be better handled, and (2) emissions from low-mass stars, which are the major contributors to a galaxy's stellar mass, can be better measured. WISE was the only mission to date that provided all-sky IR data that are deep enough for galaxy evolution studies out to z [approximately] 1 (sampling restframe K-band). The only wide-field optical survey data that could match WISE depths are those from the SDSS Stripe 82 over [about] 300 deg2 . The synergy of the two is therefore natural. The implementation, however, is of tremendous difficulty. This is mainly because of the vastly different spatial resolutions between SDSS and WISE. To overcome this problem, we take an approach that is often referred to as "morphological template fitting", i.e., using the high-resolution image to define the morphological template of the galaxy in question, and de-convolving its light profile in the low-resolution image accordingly. In this way, we obtain the SED measurements over the entire 0.3-5[mu]m range in the most self-consistent manner. Using this SED catalog as the basis, we derive photometric redshifts and stellar masses for all the 9 million galaxies that span z = 0-0.8. This provides us an unprecedented statistics when deriving galaxy stellar mass functions (MFs) and GSMD over multiple redshift bins. Some preliminary results are discussed. As a by-product of our morphological template fitting process, an interesting population of objects called "WISE Optical Dropouts" ("WoDrops" for short) are discovered. These objects are significant detections in WISE data but are invisible in all the SDSS Stripe 82 data. Their nature remains a mystery up to this point. Among all possibilities, the only viable interpretation is that they are very high-mass galaxies with very high dust extinctions. To reveal their nature, future observations at larger facilities will be necessary.

scholarly journals THE SLOAN DIGITAL SKY SURVEY QUASAR LENS SEARCH. II. STATISTICAL LENS SAMPLE FROM THE THIRD DATA RELEASE

2008 ◽  
Vol 135 (2) ◽  
pp. 496-511 ◽  
Author(s):  
Naohisa Inada ◽  
Masamune Oguri ◽  
Robert H. Becker ◽  
Min-Su Shin ◽  
Gordon T. Richards ◽  
...  
Keyword(s):  
Sloan Digital Sky Survey ◽  
The Third ◽  
Sky Survey ◽  
Data Release

scholarly journals Local AGN survey (LASr): I. Galaxy sample, infrared colour selection, and predictions for AGN within 100 Mpc

2020 ◽  
Vol 494 (2) ◽  
pp. 1784-1816
Author(s):  
D Asmus ◽  
C L Greenwell ◽  
P Gandhi ◽  
P G Boorman ◽  
J Aird ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Galaxy Evolution ◽  
Galactic Nuclei ◽  
Wide Field ◽  
X Ray ◽  
Sky Survey ◽  
Galaxy Sample ◽  
Redshift Survey ◽  
Infrared Survey

ABSTRACT To answer major questions on supermassive black hole (SMBH) and galaxy evolution, a complete census of SMBH growth, i.e. active galactic nuclei (AGN), is required. Thanks to all-sky surveys by the Wide-field Infrared Survey Explorer (WISE) and the Spectrum-Roentgen-Gamma (SRG) missions, this task is now feasible in the nearby Universe. We present a new survey, the Local AGN Survey (LASr), with the goal of identifying AGN unbiased against obscuration and determining the intrinsic Compton-thick (CT) fraction. We construct the most complete all-sky galaxy sample within 100 Mpc ($90{{\ \rm per\ cent}}$ completeness for log (M*/M⊙) ∼ 9.4), four times deeper than the current reference, the Two Micron All-Sky Survey Redshift Survey (2MRS), which misses ${\sim}20{{\ \rm per\ cent}}$ of known luminous AGN. These 49k galaxies serve as parent sample for LASr, called LASr-GPS. It contains 4.3k already known AGN, $\ge 82{{\ \rm per\ cent}}$ of these are estimated to have $L^\mathrm{nuc}(12\, \mu \mathrm{m})\lt 10^{42.3}$ erg s−1, i.e. are low-luminosity AGN. As a first method for identifying Seyfert-like AGN, we use WISE-based infrared colours, finding 221 galaxies at $L^\mathrm{nuc}(12\, \mu \mathrm{m})\ge 10^{42.3}$ erg s−1 to host an AGN at $90{{\ \rm per\ cent}}$ reliability. This includes 61 new AGN candidates and implies an optical type 2 fraction of 50–71 per cent. We quantify the efficiency of this technique and estimate the total number of AGN with $L^\mathrm{int}(\rm {2-10\,keV})\ge 10^{42}$ erg s−1 in the volume to be $362^{+145}_{-116}$ ($8.6^{+3.5}_{-2.8}\, \times$ 10−5 Mpc−3). X-ray brightness estimates indicate the CT fraction to be 40–55 per cent to explain the Swift non-detections of the infrared selected objects. One third of the AGN within 100 Mpc remain to be identified, and we discuss the prospects for the eROSITA all-sky survey to detect them.

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