- ID:
- ivo://CDS.VizieR/J/ApJS/221/13
- Title:
- ACS Fornax Cluster Survey. XI. GC candidates
- Short Name:
- J/ApJS/221/13
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present catalogs of globular cluster (GC) candidates for 43 galaxies from the ACS Fornax Cluster survey, a program designed to carry out imaging of early-type members of the Fornax cluster using the Advanded Camera for Surveys (ACS) on board the Hubble Space Telescope. The procedure to select bona fide GC candidates from the full list of detections is based on model-based clustering methods, similar to those adopted for a survey of 100 galaxies in the Virgo cluster, the ACS Virgo Cluster Survey. For each detected source, we measure its position, magnitudes in the F475W (~Sloan g) and F850LP (~Sloan z) bandpasses, half-light radii obtained by fitting point-spread function-convolved King models to the observed light distribution, and an estimate of the probability {rho}_GC_ that each cataloged source is a GC. These measurements are presented for 9136 sources, of which 6275 have {rho}_GC_>=0.5, and are thus likely GCs.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/734/L22
- Title:
- ACS Nearby Galaxy Survey Treasury
- Short Name:
- J/ApJ/734/L22
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a measurement of the age distribution of stars residing in spiral disks and dwarf galaxies. We derive a complete star formation history of the ~140Mpc^3^ covered by the volume-limited sample of galaxies in the Advanced Camera for Surveys (ACS) Nearby Galaxy Survey Treasury (ANGST). The total star formation rate density history ({rho}_SFR_(t)) is dominated by the large spirals in the volume, although the sample consists mainly of dwarf galaxies. Our {rho}_SFR_(t) shows a factor of ~3 drop at z~2, in approximate agreement with results from other measurement techniques. While our results show that the overall {rho}_SFR_(t) has decreased since z~1, the measured rates during this epoch are higher than those obtained from other measurement techniques. This enhanced recent star formation rate appears to be largely due to an increase in the fraction of star formation contained in low-mass disks at recent times. Finally, our results indicate that despite the differences at recent times, the epoch of formation of ~50% of the stellar mass in dwarf galaxies was similar to that of ~50% of the stellar mass in large spiral galaxies (z>~2), despite the observed galaxy-to-galaxy diversity among the dwarfs.
- ID:
- ivo://CDS.VizieR/J/ApJS/164/334
- Title:
- ACS Virgo Cluster Survey. VI
- Short Name:
- J/ApJS/164/334
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a detailed analysis of the morphology, isophotal parameters, and surface brightness profiles for 100 early-type members of the Virgo Cluster, from dwarfs (M_B_=-15.1mag) to giants (M_B_=-21.8mag), imaged in the g and z passbands using the Advanced Camera for Surveys (ACS) on board the Hubble Space Telescope.
- ID:
- ivo://CDS.VizieR/J/ApJ/681/197
- Title:
- ACS Virgo Cluster Survey. XV
- Short Name:
- J/ApJ/681/197
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The fraction of stellar mass contained in globular clusters (GCs), also measured by number as the specific frequency, is a fundamental quantity that reflects both a galaxy's early star formation and its entire merging history. We present specific frequencies, luminosities, and mass fractions for the globular cluster systems of 100 early-type galaxies in the ACS Virgo Cluster Survey, the largest homogeneous catalog of its kind.
- ID:
- ivo://CDS.VizieR/J/ApJS/104/185
- Title:
- A deep multicolor survey. I.
- Short Name:
- J/ApJS/104/185
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have used the Kitt Peak National Observatory 4m Mayall telescope to image 0.83 square degrees of sky in six fields at high Galactic latitude in six filters spanning 3000-10000A to magnitude limits ranging from 22.1 to 23.8. We have assembled a catalog of 21375 stellar objects detected in the fields for use primilary in conducting a multicolor search for quasars. This paper describes the data reduction techniques used on the CCD data, the methods used to construct the stellar object catalog, and the simulations performed to understand its completeness and contamination.
- ID:
- ivo://CDS.VizieR/J/ApJ/462/614
- Title:
- A deep multicolor survey. II.
- Short Name:
- J/ApJ/462/614
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have used the Kitt Peak National Observatory 4m Mayall telescope to image 0.83 square degrees of sky in six fields at high galactic latitude in six filters spanning 3000-10000A to magnitude limits ranging from 22.1 to 23.8. As a first use of this database, we have conducted a multicolor survey for quasars. We discuss various methods of selecting outliers in different color-color diagrams and multicolor space that have been used to identify quasars at all redshifts from their colors alone. We discuss the initial results of our program of spectroscopic identification which has so far resulted in the identification of over 40 faint quasars, including one a z>4, a similar number of compact narrow emission-line galaxies, and a number of unusual and potentially interesting stars. We use these spectroscopic results, along with extensive simulations of quasar spectra, to study the efficiency of our candidate selection procedures. Finally, we compare the number counts of our quasars and quasar candidates to the expected numbers based on previous studies of the quasar luminosity function. The agreement of our observations with these expectations is good in most cases. However, we do estimate that our survey contains more quasars with B<21 and z<2.3 than expected from the results published by Koo & Kron in (1988ApJ...325...92K) and more z>3 quasars than expected from the results published by Warren, Hewett & Osmer in (1994ApJ...421..412W), both at the 3 {sigma} level. Additional spectroscopic observations will be required to confirm or refute these excesses.
- ID:
- ivo://CDS.VizieR/J/AJ/114/2269
- Title:
- A deep multicolor survey. III.
- Short Name:
- J/AJ/114/2269
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have made spectroscopic identifications of 39 additional quasar candidates from the Deep Multicolor Survey (DMS) of Hall et al. (1996, Cat. <J/ApJ/462/614>). We have identified 9 new quasars with 0.3<z<2.8 and 16.8<B<21.6, all from the group of candidates with ultraviolet excess (UVX). No new quasars with z>3 were found among the observed candidates selected due to their red (B-R) and (V-R) colors. As a result, there are now 55 confirmed quasars in the survey: 42 with 0.3<z<2, nine with 2<z<3, three with 3<z<4, and 1 at z=4.3. One new quasar, DMS 0059-0055, is very bright with B=16.8 and z=0.3, making its detection by our survey very unexpected. Including this new spectroscopy, the results of the DMS are converging with the predicted space densities of other surveys. In particular, we no longer find an excess of quasars with z<2.3 and B<21 in the survey over predictions based on models by Koo & Kron (1988ApJ...325...92K). Also, the excess in the number of quasars seen at z>3 over predictions based on models by Warren et al. (1994ApJ...421..412W) is less than previously suggested. We also demonstrate the success of our quasar color modeling which is important in assessing the completeness of our survey.
- ID:
- ivo://CDS.VizieR/J/AJ/88/1285
- Title:
- A deep survey of galaxies
- Short Name:
- J/AJ/88/1285
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a sample of galaxies in six fields, each of area 2 sq deg, located in the North and South galactic polar caps. Photoelectrically calibrated photographic magnitudes and J-F colors have been determined for 512 galaxies brighter than completeness limits which range from F=16.5 to F=17.2 among the fields. Velocities, with typical accuracies of 150km/s have been obtained for 280 of the brighter galaxies. Using these data and previously published work, we determine the general galaxy luminosity function parameters to be M*_F_=-22.7, {alpha}=-1.25, and the mean visual luminosity density of the universe to be {rho}=2.3x10^8^hL_{sun}_/Mpc^3^. Assuming M/L_v_=300h, this implies {OMEGA}~0.26.
- ID:
- ivo://CDS.VizieR/J/MNRAS/273/157
- Title:
- A faint galaxy survey to B = 24.
- Short Name:
- J/MNRAS/273/157
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the multi-slit LDSS-2 spectrograph on the William Herschel Telescope we have completed a redshift survey in the magnitude range 22.5<B<24 which produced 73 redshifts representing a 73% complete sample uniformly selected from four deep fields at high galactic latitude. The survey extends to z>1 and includes the highest redshift galaxy (z=1.108) yet discovered in a field sample.
- ID:
- ivo://CDS.VizieR/J/ApJ/693/1840
- Title:
- A3266 galaxies at 24um
- Short Name:
- J/ApJ/693/1840
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Multiband Imaging Photometer observations of the cluster A3266. About 100 spectroscopic cluster members have been detected at 24um. The infrared (IR) luminosity function (LF) in A3266 is very similar to that in the Coma cluster down to the detection limit LIR~10^43^erg/s, suggesting a universal form of the bright-end IR LF for local rich clusters with M~10^15^M_{sun}_. The shape of the bright end of the A3266-Coma composite IR LF is not significantly different from that of nearby field galaxies, but the fraction of IR-bright galaxies (star formation rate (SFR)>0.2M_{sun}_/yr) in both clusters increases with cluster-centric radius. The decrease of the blue galaxy fraction toward the high-density cores only accounts for part of the trend; the fraction of red galaxies with moderate SFRs (0.2M_{sun}_/yr<SFR<1M_{sun}/yr) also decreases with increasing galaxy density. These results suggest that for the IR-bright galaxies nearby rich clusters are distinguished from the field by a lower star forming galaxy fraction, but not by a change in L*_IR_.