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1391. Passive red spirals in Galaxy Zoo
ID:
ivo://CDS.VizieR/J/MNRAS/405/783
Title:
Passive red spirals in Galaxy Zoo
Short Name:
J/MNRAS/405/783
Date:
21 Oct 2021
Publisher:
CDS
Description:
We study the spectroscopic properties and environments of red (or passive) spiral galaxies found by the Galaxy Zoo project. By carefully selecting face-on disc-dominated spirals, we construct a sample of truly passive discs (i.e. they are not dust reddened spirals, nor are they dominated by old stellar populations in a bulge). As such, our red spirals represent an interesting set of possible transition objects between normal blue spiral galaxies and red early types, making up ~6 per cent of late-type spirals. We use optical images and spectra from Sloan Digital Sky Survey to investigate the physical processes which could have turned these objects red without disturbing their morphology.
1392. Peculiar velocities in 6dFGS
ID:
ivo://CDS.VizieR/J/MNRAS/445/2677
Title:
Peculiar velocities in 6dFGS
Short Name:
J/MNRAS/445/2677
Date:
21 Oct 2021
Publisher:
CDS
Description:
We derive peculiar velocities for the 6dF Galaxy Survey (6dFGS) and describe the velocity field of the nearby (z<0.055) Southern hemisphere. The survey comprises 8885 galaxies for which we have previously reported Fundamental Plane data. We obtain peculiar velocity probability distributions for the redshift-space positions of each of these galaxies using a Bayesian approach. Accounting for selection bias, we find that the logarithmic distance uncertainty is 0.11 dex, corresponding to 26 per cent in linear distance. We use adaptive kernel smoothing to map the observed 6dFGS velocity field out to cz~16000km/s, and compare this to the predicted velocity fields from the PSCz Survey and the 2MASS Redshift Survey. We find a better fit to the PSCz prediction, although the reduced {chi}^2^ for the whole sample is approximately unity for both comparisons. This means that, within the observational uncertainties due to redshift-independent distance errors, observed galaxy velocities and those predicted by the linear approximation from the density field agree. However, we find peculiar velocities that are systematically more positive than model predictions in the direction of the Shapley and Vela superclusters, and systematically more negative than model predictions in the direction of the Pisces-Cetus Supercluster, suggesting contributions from volumes not covered by the models.
1393. PHAT stellar cluster survey. II. AP catalog
ID:
ivo://CDS.VizieR/J/ApJ/802/127
Title:
PHAT stellar cluster survey. II. AP catalog
Short Name:
J/ApJ/802/127
Date:
21 Oct 2021
Publisher:
CDS
Description:
We construct a stellar cluster catalog for the Panchromatic Hubble Andromeda Treasury (PHAT) survey using image classifications collected from the Andromeda Project (AP) citizen science website. We identify 2753 clusters and 2270 background galaxies within ~0.5deg^2^ of PHAT imaging searched, or ~400kpc^2^ in deprojected area at the distance of the Andromeda Galaxy (M31). These identifications result from 1.82million classifications of ~20000 individual images (totaling ~7gigapixels) by tens of thousands of volunteers. We show that our crowd-sourced approach, which collects >80 classifications per image, provides a robust, repeatable method of cluster identification. The high spatial resolution Hubble Space Telescope images resolve individual stars in each cluster and are instrumental in the factor of ~6 increase in the number of clusters known within the survey footprint. We measure integrated photometry in six filter passbands, ranging from the near-UV to the near-IR. PHAT clusters span a range of ~8 magnitudes in F475W (g-band) luminosity, equivalent to ~4 decades in cluster mass. We perform catalog completeness analysis using >3000 synthetic cluster simulations to determine robust detection limits and demonstrate that the catalog is 50% complete down to ~500M_{sun}_ for ages <100Myr. We include catalogs of clusters, background galaxies, remaining unselected candidates, and synthetic cluster simulations, making all information publicly available to the community. The catalog published here serves as the definitive base data product for PHAT cluster science, providing a census of star clusters in an L^*^ spiral galaxy with unmatched sensitivity and quality.
1394. PHAT stellar cluster survey. I. Year 1
ID:
ivo://CDS.VizieR/J/ApJ/752/95
Title:
PHAT stellar cluster survey. I. Year 1
Short Name:
J/ApJ/752/95
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Panchromatic Hubble Andromeda Treasury (PHAT) survey is an ongoing Hubble Space Telescope (HST) multi-cycle program to obtain high spatial resolution imaging of one-third of the M31 disk at ultraviolet through near-infrared wavelengths. In this paper, we present the first installment of the PHAT stellar cluster catalog. When completed, the PHAT cluster catalog will be among the largest and most comprehensive surveys of resolved star clusters in any galaxy. The exquisite spatial resolution achieved with HST has allowed us to identify hundreds of new clusters that were previously inaccessible with existing ground-based surveys. We identify 601 clusters in the Year 1 sample, representing more than a factor of four increase over previous catalogs within the current survey area (390 arcmin^2^). This work presents results derived from the first ~25% of the survey data; we estimate that the final sample will include ~2500 clusters. For the Year 1 objects, we present a catalog with positions, radii, and six-band integrated photometry. Along with a general characterization of the cluster luminosities and colors, we discuss the cluster luminosity function, the cluster size distributions, and highlight a number of individually interesting clusters found in the Year 1 search.
1395. PHAT X. UV-IR photometry of M31 stars
ID:
ivo://CDS.VizieR/J/ApJS/215/9
Title:
PHAT X. UV-IR photometry of M31 stars
Short Name:
J/ApJS/215/9
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have measured stellar photometry with the Hubble Space Telescope Wide Field Camera 3 (WFC3) and Advanced Camera for Surveys in near ultraviolet (F275W, F336W), optical (F475W, F814W), and near infrared (F110W, F160W) bands for 117 million resolved stars in M31. As part of the Panchromatic Hubble Andromeda Treasury survey, we measured photometry with simultaneous point-spread function (PSF) fitting across all bands and at all source positions after precise astrometric image alignment (<5-10mas accuracy). In the outer disk, the photometry reaches a completeness-limited depth of F475W~28, while in the crowded, high surface brightness bulge, the photometry reaches F475W~25. We find that simultaneous photometry and optimized measurement parameters significantly increase the detection limit of the lowest-resolution filters (WFC3/IR) providing color-magnitude diagrams (CMDs) that are up to 2.5mag deeper when compared with CMDs from WFC3/IR photometry alone. We present extensive analysis of the data quality including comparisons of luminosity functions and repeat measurements, and we use artificial star tests to quantify photometric completeness, uncertainties and biases. We find that the largest sources of systematic error in the photometry are due to spatial variations in the PSF models and charge transfer efficiency corrections.
1396. PHAT. XVI. Star cluster masses and ages
ID:
ivo://CDS.VizieR/J/ApJ/827/33
Title:
PHAT. XVI. Star cluster masses and ages
Short Name:
J/ApJ/827/33
Date:
21 Oct 2021
Publisher:
CDS
Description:
We use the Panchromatic Hubble Andromeda Treasury survey data set to perform spatially resolved measurements of star cluster formation efficiency ({Gamma}), the fraction of stellar mass formed in long-lived star clusters. We use robust star formation history and cluster parameter constraints, obtained through color-magnitude diagram analysis of resolved stellar populations, to study Andromeda's cluster and field populations over the last ~300Myr. We measure {Gamma} of 4%-8% for young, 10-100Myr-old populations in M31. We find that cluster formation efficiency varies systematically across the M31 disk, consistent with variations in mid-plane pressure. These {Gamma} measurements expand the range of well-studied galactic environments, providing precise constraints in an HI-dominated, low-intensity star formation environment. Spatially resolved results from M31 are broadly consistent with previous trends observed on galaxy-integrated scales, where {Gamma} increases with increasing star formation rate surface density ({Sigma}_SFR_). However, we can explain observed scatter in the relation and attain better agreement between observations and theoretical models if we account for environmental variations in gas depletion time ({tau}_dep_) when modeling {Gamma}, accounting for the qualitative shift in star formation behavior when transitioning from a H_2_-dominated to a HI-dominated interstellar medium. We also demonstrate that {Gamma} measurements in high {Sigma}_SFR_ starburst systems are well-explained by {tau}_dep_-dependent fiducial {Gamma} models.
1397. Phoenix Deep Survey 1.4-GHz microJy Catalog
ID:
ivo://CDS.VizieR/J/AJ/125/465
Title:
Phoenix Deep Survey 1.4-GHz microJy Catalog
Short Name:
J/AJ/125/465
Date:
21 Oct 2021
Publisher:
CDS
Description:
The initial Phoenix Deep Survey (PDS) observations with the Australia Telescope Compact Array have been supplemented by additional 1.4 GHz observations over the past few years. Here we present details of the construction of a new mosaic image covering an area of 4.56 deg2, an investigation of the reliability of the source measurements, and the 1.4 GHz source counts for the compiled radio catalog. The mosaic achieves a 1-sigma rms noise of 12 microJy at its most sensitive, and a homogeneous radio-selected catalog of over 2000 sources reaching flux densities as faint as 60 microJy has been compiled. The source parameter measurements are found to be consistent with the expected uncertainties from the image noise levels and the Gaussian source fitting procedure. A radio-selected sample avoids the complications of obscuration associated with optically selected samples, and by utilizing complementary PDS observations, including multicolor optical, near-infrared, and spectroscopic data, this radio catalog will be used in a detailed investigation of the evolution in star formation spanning the redshift range 0 < z < 1. The homogeneity of the catalog ensures a consistent picture of galaxy evolution can be developed over the full cosmologically significant redshift range of interest.
1398. Phoenix Deep Survey: 1.4-GHz source counts
ID:
ivo://CDS.VizieR/J/MNRAS/296/839
Title:
Phoenix Deep Survey: 1.4-GHz source counts
Short Name:
J/MNRAS/296/839
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the first results from the Phoenix Deep Survey, a multiwavelength survey of a 2 deg diameter region. Observations in the radio continuum at 1.4 GHz carried out with the Australia Telescope Compact Array are described. The catalogue of over 1000 radio sources compiled from these observations is analyzed, and the source counts are presented. We model the observational source counts using a two-population model and published luminosity functions for these populations. Upon invoking luminosity and density evolution, we find that a luminosity evolution model best fits the radio observations, consistent with earlier work. The redshift distribution of the two galaxy populations investigated is also modeled and discussed.
1399. Phoenix Deep Survey spectroscopic catalog
ID:
ivo://CDS.VizieR/J/ApJ/624/135
Title:
Phoenix Deep Survey spectroscopic catalog
Short Name:
J/ApJ/624/135
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Phoenix Deep Survey is a multiwavelength survey based on deep 1.4GHz radio imaging, reaching well into the sub-100uJy level. One of the aims of this survey is to characterize the submillijansky radio population, exploring its nature and evolution. In this paper we present the catalog and results of the spectroscopic observations aimed at characterizing the optically "bright" (R<~21.5mag) counterparts of faint radio sources. Of 371 sources with redshift determination, 21% have absorption lines only, 11% show active galactic nucleus signatures, 32% are star-forming galaxies, 34% show narrow emission lines that do not allow detailed spectral classification (owing to poor signal-to-noise ratio and/or lack of diagnostic emission lines), and the remaining 2% are identified with stars.
1400. Photometric Catalog of the Deep Ecliptic Survey
ID:
ivo://CDS.VizieR/J/ApJS/194/40
Title:
Photometric Catalog of the Deep Ecliptic Survey
Short Name:
J/ApJS/194/40
Date:
21 Oct 2021
Publisher:
CDS
Description:
A photometric catalog, developed for the calibration of the Deep Ecliptic Survey, is presented. The catalog contains 213272 unique sources that were measured in V and R filters and transformed to the Johnson-Cousins systems using the Landolt standard catalog. All of the sources lie within 6{deg} of the ecliptic and cover all longitudes except for the densest stellar regions nearest the galactic center. Seventeen percent of the sources in the catalog are derived from three or more nights of observation. The catalog contains sources as faint as R~19 but the largest fraction fall in the R~15-16 (V~16-17)mag range. All magnitude bins down to R=19 have a significant fraction of objects with uncertainties <=0.1mag.

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