- ID:
- ivo://CDS.VizieR/J/AJ/121/2381
- Title:
- UBRI photometry of radio galaxies
- Short Name:
- J/AJ/121/2381
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe a new estimate of the radio galaxy 1.4 GHz luminosity function and its evolution at intermediate redshifts (z~0.4). Photometric redshifts and color selection have been used to select B_J_<23.5 early-type galaxies from the Panoramic Deep Fields, a multicolor survey of two 25deg^2^ fields. Approximately 230 radio galaxies have then been selected by matching early-type galaxies with NVSS radio sources brighter than 5mJy. Estimates of the 1.4GHz luminosity function of radio galaxies measure significant evolution over the observed redshift range. For an {Omega}_M_=1 cosmology the evolution of the radio power is consistent with luminosity evolution where P(z)~P(0)(1+z)^K_L_^ and 3<K_L_<5. The observed evolution is similar to that observed for UVX and X-ray selected active galactic nuclei and is consistent with the same physical process being responsible for the optical and radio luminosity evolution of active galactic nuclei.
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Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/126/632
- Title:
- UBVRIz'HK' photometry of 2Ms CDFN X-ray sources
- Short Name:
- J/AJ/126/632
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an optical and near-infrared catalog for the X-ray sources in the 2Ms Chandra observation of the Hubble Deep Field North region. We have high-quality multicolor imaging data for all 503 X-ray point sources in the X-ray-selected catalog and reliable spectroscopic redshifts for 284. We spectroscopically identify six high-redshift (z>1) type II quasars (L_2-8keV_>10^44^ergs/s) in our sample. Our spectroscopic completeness for the R<=24 sources is 87%. The spectroscopic redshift distribution shows two broad redshift spikes that have clearly grown over those originally seen in the 1Ms exposure. The spectroscopically identified extragalactic sources already comprise 75% of the measured 2-8keV light. Redshift slices versus 2-8keV flux show that an impressive 54% of the measured 2-8keV light arises from sources at z<1 and 68% from sources at z<2.
- ID:
- ivo://CDS.VizieR/J/AJ/151/33
- Title:
- UBVRIz light curves of 51 Type II supernovae
- Short Name:
- J/AJ/151/33
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a compilation of UBVRIz light curves of 51 type II supernovae discovered during the course of four different surveys during 1986-2003: the Cerro Tololo Supernova Survey, the Calan/Tololo Supernova Program (C&T), the Supernova Optical and Infrared Survey (SOIRS), and the Carnegie Type II Supernova Survey (CATS). The photometry is based on template-subtracted images to eliminate any potential host galaxy light contamination, and calibrated from foreground stars. This work presents these photometric data, studies the color evolution using different bands, and explores the relation between the magnitude at maximum brightness and the brightness decline parameter (s) from maximum light through the end of the recombination phase. This parameter is found to be shallower for redder bands and appears to have the best correlation in the B band. In addition, it also correlates with the plateau duration, being shorter (longer) for larger (smaller) s values.
- ID:
- ivo://CDS.VizieR/J/A+A/528/A36
- Title:
- u*g'r'i' photometry of A496 faint LSB galaxies
- Short Name:
- J/A+A/528/A36
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Cluster faint low surface brightness galaxies (fLSBs) are difficult to observe. Consequently, their origin, physical properties and number density are not well known. After a first search for fLSBs in the highly substructured Coma cluster, we present here a search for fLSBs in the nearly relaxed Abell 496 cluster. Abell 496 appears to be a much more relaxed cluster than Coma, but still embedded in a large scale filament of galaxies. Our aim is to compare the properties of fLSBs in these two very different clusters, to search for environmental effects.
- ID:
- ivo://CDS.VizieR/J/AJ/119/2598
- Title:
- u'g'r'i'z' photometry of LCRS galaxies
- Short Name:
- J/AJ/119/2598
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present high-quality photometry in the five Sloan Digital Sky Survey filters, u', g', r', i', and z', for 2195 galaxies with spectroscopic redshifts measured by the Las Campanas Redshift Survey. In addition, a polynomial photometric redshift estimator is derived, with an uncertainty of 0.035 out to z=0.25.
- ID:
- ivo://CDS.VizieR/J/ApJ/778/127
- Title:
- UKIDSS+FIRST+SDSS red QSOs candidates
- Short Name:
- J/ApJ/778/127
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a pilot survey to find dust-reddened quasars by matching the Faint Images of the Radio Sky at Twenty-Centimeters (FIRST) radio catalog to the UKIDSS near-infrared survey and using optical data from Sloan Digital Sky Survey to select objects with very red colors. The deep K-band limit provided by UKIDSS allows for finding more heavily reddened quasars at higher redshifts as compared with previous work using FIRST and Two Micron All Sky Survey (2MASS). We selected 87 candidates with K<=17.0 from the UKIDSS Large Area Survey (LAS) First Data Release (DR1), which covers 190deg^2^. These candidates reach up to ~1.5mag below the 2MASS limit and obey the color criteria developed to identify dust-reddened quasars. We have obtained 61 spectroscopic observations in the optical and/or near-infrared, as well as classifications in the literature, and have identified 14 reddened quasars with E(B-V)>0.1, including 3 at z>2. We study the infrared properties of the sample using photometry from the Wide-Field Infrared Survey Explorer and find that infrared colors improve the efficiency of red quasar selection, removing many contaminants in an infrared-to-optical color-selected sample alone. The highest-redshift quasars (z>~2) are only moderately reddened, with E(B-V)~0.2-0.3. We find that the surface density of red quasars rises sharply with faintness, comprising up to 17% of blue quasars at the same apparent K-band flux limit. We estimate that to reach more heavily reddened quasars (i.e., E(B-V)>~0.5) at z>2 and a depth of K=17, we would need to survey at least ~2.5 times more area.
- ID:
- ivo://CDS.VizieR/J/MNRAS/475/4148
- Title:
- UKIDSS UDS field spectroscopic redshifts
- Short Name:
- J/MNRAS/475/4148
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a large-scale galaxy structure Cl J021734-0513 at z~0.65 discovered in the UKIDSS UDS field, made of ~20 galaxy groups and clusters, spreading over 10Mpc. We report on a VLT/VIMOS spectroscopic follow-up program that, combined with past spectroscopy, allowed us to confirm four galaxy clusters (M_200_~10^14^M_{sun}_) and a dozen associated groups and star-forming galaxy overdensities. Two additional filamentary structures at z~0.62 and 0.69 and foreground and background clusters at 0.6<z<0.7 were also confirmed along the line of sight. The structure subcomponents are at different formation stages. The clusters have a core dominated by passive galaxies and an established red sequence. The remaining structures are a mix of star-forming galaxy overdensities and forming groups. The presence of quiescent galaxies in the core of the latter shows that 'pre-processing' has already happened before the groups fall into their more massive neighbours. Our spectroscopy allows us to derive spectral index measurements e.g. emission/absorption line equivalent widths, strength of the 4000{AA} break, valuable to investigate the star formation history of structure members. Based on these line measurements, we select a population of 'post-starburst' galaxies. These galaxies are preferentially found within the virial radius of clusters, supporting a scenario in which their recent quenching could be prompted by gas stripping by the dense intracluster medium. We derive stellar age estimates using Markov Chain Monte Carlo-based spectral fitting for quiescent galaxies and find a correlation between ages and colours/stellar masses which favours a top-down formation scenario of the red sequence. A catalogue of ~650 redshifts in UDS is released alongside the paper (via MNRAS online data).
- ID:
- ivo://CDS.VizieR/J/ApJ/768/77
- Title:
- Ultra-compact high velocity clouds from ALFALFA
- Short Name:
- J/ApJ/768/77
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of 59 ultra-compact high velocity clouds (UCHVCs) extracted from the 40% complete ALFALFA HI-line survey. The ALFALFA UCHVCs have median flux densities of 1.34Jy.km/s, median angular diameters of 10', and median velocity widths of 23km/s. We show that the full UCHVC population cannot easily be associated with known populations of high velocity clouds. Of the 59 clouds presented here, only 11 are also present in the compact cloud catalog extracted from the commensal GALFA-HI survey, demonstrating the utility of this separate dataset and analysis. Based on their sky distribution and observed properties, we infer that the ALFALFA UCHVCs are consistent with the hypothesis that they may be very low mass galaxies within the Local Volume. In that case, most of their baryons would be in the form of gas, and because of their low stellar content, they remain unidentified by extant optical surveys. At distances of ~1Mpc, the UCHVCs have neutral hydrogen (HI) masses of ~10^5^-10^6^M_{sun}_, HI diameters of ~2-3kpc, and indicative dynamical masses within the HI extent of ~10^7^-10^8^M_{sun}_, similar to the Local Group ultra-faint dwarf Leo T. The recent ALFALFA discovery of the star-forming, metal-poor, low mass galaxy Leo P demonstrates that this hypothesis is true in at least one case. In the case of the individual UCHVCs presented here, confirmation of their extragalactic nature will require further work, such as the identification of an optical counterpart to constrain their distance.
- ID:
- ivo://CDS.VizieR/J/AJ/125/1107
- Title:
- Ultra-deep near-IR observation in HDF-S
- Short Name:
- J/AJ/125/1107
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep near-infrared (NIR) Js-, H-, and Ks-band ISAAC imaging of the Wide Field Planetary Camera 2 (WFPC2) field of the Hubble Deep Field South (HDF-S). The 2.5'x2.5' high Galactic latitude field was observed with the Very Large Telescope under the best seeing conditions, with integration times amounting to 33.6hr in Js, 32.3hr in H, and 35.6hr in Ks. We reach total AB magnitudes for point sources of 26.8, 26.2, and 26.2, respectively (3sigma), which make it the deepest ground-based NIR observation to date and the deepest Ks-band data in any field. The effective seeing of the co-added images is ~0.45" in Js, ~0.48" in H, and ~0.46" in Ks. Using published WFPC2 optical data, we constructed a Ks-limited multicolor catalog containing 833 sources down to K^tot^_s,AB_<~26, of which 624 have seven-band optical-to-NIR photometry. These data allow us to select normal galaxies from their rest-frame optical properties to high redshift (z<~4). The observations, data reduction, and properties of the final images are discussed, and we address the detection and photometry procedures that were used in making the catalog. In addition, we present deep number counts, color distributions, and photometric redshifts of the HDF-S galaxies.
- ID:
- ivo://CDS.VizieR/J/ApJ/923/257
- Title:
- Ultra-diffuse galaxies with spectroscopic obs.
- Short Name:
- J/ApJ/923/257
- Date:
- 14 Mar 2022 07:42:35
- Publisher:
- CDS
- Description:
- We present new redshift measurements for 19 candidate ultra-diffuse galaxies (UDGs) from the Systematically Measuring Ultra-Diffuse Galaxies (SMUDGes) survey after conducting a long-slit spectroscopic follow-up campaign on 23 candidates with the Large Binocular Telescope. We combine these results with redshift measurements from other sources for 29 SMUDGes and 20 non-SMUDGes candidate UDGs. Together, this sample yields 44 spectroscopically confirmed UDGs (r_e_>=1.5kpc and {mu}_g_(0)>=24mag/arcsec^2^ within uncertainties) and spans cluster and field environments, with all but one projected on the Coma cluster and environs. We find no statistically significant differences in the structural parameters of cluster and noncluster confirmed UDGs, although there are hints of differences among the axis ratio distributions. Similarly, we find no significant structural differences among those in locally dense or sparse environments. However, we observe a significant difference in color with respect to projected clustercentric radius, confirming trends observed previously in statistical UDG samples. This trend strengthens further when considering whether UDGs reside in either cluster or locally dense environments, suggesting starkly different star formation histories for UDGs residing in high- and low-density environments. Of the 16 large (r_e_>=3.5kpc) UDGs in our sample, only one is a field galaxy that falls near the early-type galaxy red sequence. No other field UDGs found in low-density environments fall near the red sequence. This finding, in combination with our detection of Galaxy Evolution Explorer NUV flux in nearly half of the UDGs in sparse environments, suggests that field UDGs are a population of slowly evolving galaxies.
