- ID:
- ivo://CDS.VizieR/J/ApJ/727/47
- Title:
- The MgII cross-section of red galaxies
- Short Name:
- J/ApJ/727/47
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe a search for MgII(2796, 2803) absorption lines in Sloan Digital Sky Survey (SDSS) spectra of QSOs whose lines of sight pass within impact parameters {rho}~200kpc of galaxies with photometric redshifts of z=0.46-0.6 and errors {Delta}z~0.05. The galaxies selected have the same colors and luminosities as the Luminous Red Galaxy (LRG) population previously selected from the SDSS. A search for MgII lines within a redshift interval of +/-0.1 of a galaxy's photometric redshift shows that absorption by these galaxies is rare: the covering fraction is f({rho})~10%-15% between {rho}=20kpc and {rho}=100kpc, for MgII lines with rest equivalent widths of W_r_>=0.6{AA}, falling to zero at larger {rho}. There is no evidence that W_r_ correlates with impact parameter or galaxy luminosity.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJS/197/33
- Title:
- The M87 globular cluster system
- Short Name:
- J/ApJS/197/33
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the most extensive combined photometric and spectroscopic study to date of the enormous globular cluster (GC) system around M87, the central giant elliptical galaxy in the nearby Virgo Cluster. Using observations from DEIMOS and the Low Resolution Imaging Spectrometer at Keck, and Hectospec on the Multiple Mirror Telescope, we derive new, precise radial velocities for 451 GCs around M87, with projected radii from ~5 to 185kpc. We combine these measurements with literature data for a total sample of 737 objects, which we use for a re-examination of the kinematics of the GC system of M87. The velocities are analyzed in the context of archival wide-field photometry and a novel Hubble Space Telescope catalog of half-light radii, which includes sizes for 344 spectroscopically confirmed clusters. We use this unique catalog to identify 18 new candidate ultracompact dwarfs and to help clarify the relationship between these objects and true GCs.
- ID:
- ivo://CDS.VizieR/J/AJ/123/2402
- Title:
- The microJansky sky at 8.4GHz
- Short Name:
- J/AJ/123/2402
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results from two deep radio integrations at 8.4 GHz using the Very Large Array. One of the fields, at 13h, +43{deg} (SA 13 field), has an rms noise level of 1.49{mu}Jy and is the deepest radio image yet made. Thirty-four sources in a complete sample were detected above 7.5{mu}Jy, and 25 are optically identified to a limit of I=25.8, using our deep Hubble Space Telescope and ground-based images. The radio sources are usually located within 0.5" (typically 5kpc) of a galaxy nucleus and generally have a diameter less than 2.5". We have also analyzed a complete flux density-limited sample at 8.4GHz of 89 sources from five deep radio surveys, including the Hubble deep and flanking fields, as well as the two new fields. Half of all the optical counterparts are with galaxies brighter than I=23mag, but 20% are fainter than I=25.5mag. There may be a small tendency for the microJansky radio sources to prefer multigalaxy systems. The distribution of the radio spectral index between 1.4 and 8.4GHz peaks at {alpha}~-0.75 (S~{nu}^+{alpha}^) with a median value of -0.6. The average spectral index becomes steeper (lower values) for sources below 35{mu}Jy and for sources identified with optical counterparts fainter than I=25.5mag. This correlation suggests that there is an increasing contribution from starburst galaxies compared to AGNs at lower radio flux densities and fainter optical counterparts. The differential radio count between 7.5 and 1000{mu}Jy has a slope of -2.11+/-0.13 and a surface density of 0.64 sources (arcmin)^-2^ with a flux density greater than 7.5{mu}Jy.
- ID:
- ivo://CDS.VizieR/J/ApJS/193/26
- Title:
- The M33 synoptic stellar survey. I.
- Short Name:
- J/ApJS/193/26
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have conducted a ground-based BVI synoptic survey of the Local Group galaxy M33 which covers most of its disk and spans a period of 7 years. The survey targets luminous, long-period variables such as Cepheids and Miras and combines images from the DIRECT project and follow-up observations at the WIYN 3.5m telescope. This paper, the first in a series, presents the discovery and characterization of 564 Cepheid variables, which represent a factor of two increase over previous samples with calibrated point-spread function (PSF) photometry. We also describe the details of the observations and analysis of the survey data, including the use of archival Hubble Space Telescope images to characterize biases in our ground-based PSF photometry.
- ID:
- ivo://CDS.VizieR/J/AJ/153/170
- Title:
- The M33 Synoptic Stellar Survey. II. Mira variables
- Short Name:
- J/AJ/153/170
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the discovery of 1847 Mira candidates in the Local Group galaxy M33 using a novel semi-parametric periodogram technique coupled with a random forest classifier. The algorithms were applied to ~2.4*10^5^ I-band light curves previously obtained by the M33 Synoptic Stellar Survey. We derive preliminary period-luminosity relations at optical, near-infrared, and mid-infrared wavelengths and compare them to the corresponding relations in the Large Magellanic Cloud.
- ID:
- ivo://CDS.VizieR/J/A+A/576/A126
- Title:
- The 2009 multiwavelength campaign on Mrk421
- Short Name:
- J/A+A/576/A126
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We perform an extensive characterization of the broadband emission of Mrk 421, as well as its temporal evolution, during the non-flaring (low) state. The high brightness and nearby location (z=0.031) of Mrk 421 make it an excellent laboratory to study blazar emission. The goal is to learn about the physical processes responsible for the typical emission of Mrk 421, which might also be extended to other blazars that are located farther away and hence are more difficult to study. We performed a 4.5-month multi-instrument campaign on Mrk 421 between January 2009 and June 2009, which included VLBA, F- GAMMA, GASP-WEBT, Swift, RXTE, Fermi-LAT, MAGIC, and Whipple, among other instruments and collaborations. This extensive radio to very-high-energy (VHE; E>100GeV) gamma-ray dataset provides excellent temporal and energy coverage, which allows detailed studies of the evolution of the broadband spectral energy distribution.
- ID:
- ivo://CDS.VizieR/J/MNRAS/482/5167
- Title:
- The 2M-ZoA galaxy catalogue
- Short Name:
- J/MNRAS/482/5167
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a homogeneous 2MASS bright galaxy catalogue at low Galactic latitudes (|b|<=10.0{deg}, called Zone of Avoidance) which is complete to a Galactic extinction-corrected magnitude of KS^o^<=11.25m. It also includes galaxies in regions of high foreground extinctions (E(B-V)>0.95mag) situated at higher latitudes. This catalogue forms the basis of studies of large-scale structures, flow fields and extinction across the ZoA and complements the ongoing 2MASS Redshift and Tully-Fisher surveys. It comprises 3763 galaxies, 70% of which have at least one radial velocity measurement in the literature. The catalogue is complete up to star density levels of logN*/deg^2^<4.5 and at least for A(K)<0.6mag and likely as high as A(K)=20mag. Thus the ZoA in terms of bright NIR galaxies covers only 2.5-4% of the whole sky. We use a diameter-dependent extinction correction to compare our sample with an unobscured, high-latitude sample. While the correction to the Ks -band magnitude is sufficient, the corrected diameters are too small by about 4" on average. The omission of applying such a diameter-dependent extinction correction may lead to a biased flow field even at intermediate extinction values as found in the 2MRS survey. A slight dependence of galaxy colour with stellar density indicates that unsubtracted foreground stars make galaxies appear bluer. Furthermore, far-infrared sources in the DIRBE/IRAS extinction maps that were not removed at low latitudes affect the foreground extinction corrections of three galaxies and may weakly affect a further estimated ~20% of our galaxies.
- ID:
- ivo://CDS.VizieR/J/A+A/654/A117
- Title:
- The nature of hyper luminous infrared galaxies
- Short Name:
- J/A+A/654/A117
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- Hyperluminous infrared galaxies (HLIRGs) are shown to have been more abundant in early epochs. The small samples used in earlier studies are not sufficient to draw robust statistical conclusions regarding the physical properties and the power sources of these extreme infrared (IR) bright galaxies. We make use of multi-wavelength data of a large hyper luminous galaxy sample to derive the main physical properties, such as stellar mass, star formation rate (SFR), volume density, and the contribution to the cosmic stellar mass density and the cosmic SFR density. We also study the black hole (BH) growth rate and its relationship with the SFR of the host galaxy. We selected 526 HLIRGs in three deep fields (Bootes, Lockman-Hole, and ELAIS-N1) and adopted two spectral energy distribution (SED) fitting codes: CIGALE, which assumes energy balance, and CYGNUS, which is based on radiative transfer models and does not adopt an energy balance principle. We used two different active galactic nucleus (AGN) models in CIGALE and three AGN models in CYGNUS to compare results that were estimated using different SED fitting codes and a range of AGN models. The stellar mass, total IR luminosity, and AGN luminosity agree well among different models, with a typical median offset of 0.1dex. The SFR estimates show the largest dispersions (up to 0.5dex). This dispersion has an impact on the subsequent analysis, which may suggest that the previous contradictory results could partly have been due to the different choices in methods. HLIRGs are ultra-massive galaxies, with 99% of them having stellar masses larger than 10^11^M_{sun}_. Our results reveal a higher space density of ultra-massive galaxies than what was found by previous surveys or predicted via simulations. We find that HLIRGs contribute more to the cosmic SFR density as redshift increases. In terms of BH growth, the two SED fitting methods provide different results. We can see a clear trend in whereby SFR decreases as AGN luminosity increases when using CYGNUS estimates. This may possibly imply quenching by AGN in this case, whereas this trend is much weaker when using CIGALE estimates. This difference is also influenced by the dispersion between SFR estimates obtained by the two codes.
- ID:
- ivo://CDS.VizieR/J/ApJ/858/11
- Title:
- The NIR tip of RGB. I. JHK photometry of IC1613
- Short Name:
- J/ApJ/858/11
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Based on observations from the FourStar near-infrared camera on the 6.5m Baade-Magellan telescope at Las Campanas, Chile, we present calibrations of the JHK luminosities of stars defining the tip of the red giant branch (TRGB) in the halo of the Local Group dwarf galaxy IC1613. We employ metallicity- independent (rectified) T-band magnitudes-constructed using J-, H-, and K-band magnitudes and both (J-H) and (J-K) colors to flatten the upward-sloping red giant branch tips as otherwise seen in their apparent color-magnitude diagrams. We describe and quantify the advantages of working at these particular near-infrared wavelengths, which are applicable to both the Hubble Space Telescope (HST) and the James Webb Space Telescope (JWST). We also note that these same wavelengths can be accessed from the ground for an eventual tie-in to Gaia for absolute astrometry and parallaxes to calibrate the intrinsic luminosity of the TRGB. Adopting the color terms derived from the IC 1613 data, as well as the zero points from a companion study of the Large Magellanic Cloud, whose distance is anchored to the geometric distances of detached eclipsing binaries, we find a true distance modulus of 24.32+/-0.02 (statistical) +/-0.05mag (systematic) for IC 1613, which compares favorably with the recently published multi-wavelength, multi-method consensus modulus of 24.30+/-0.05mag by Hatt et al. (2017, J/ApJ/845/146).
- ID:
- ivo://CDS.VizieR/J/ApJS/243/14
- Title:
- The Ogle et al. Galaxy Catalog (OGC)
- Short Name:
- J/ApJS/243/14
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of the 1525 most optically luminous galaxies from the Sloan Digital Sky Survey with r-band luminosity L_r_>8L* and redshift z<0.3, including 84 super spirals, 15 super lenticulars, 14 super post-merger galaxies, and 1400 giant ellipticals. With mass in stars of 10^11.3^-10^12^M_{sun}_, super spirals and lenticulars are the most massive disk galaxies currently known. The specific star formation rates of super spirals place them on or below the star-forming main sequence. They must have formed stars at a high rate throughout their history in order to grow their massive, gigantic stellar disks and maintain their blue u-r integrated colors. Their disks are red on the inside and blue on the outside, consistent with inside-out growth. They tend to have small bulge-to-total (B/T) r-band luminosity ratios, characteristic of disk building via minor mergers and cold accretion. A large percentage of super disk galaxies (41%) have double nuclei, double disks, or other signatures of ongoing mergers. Most (72%) are found in moderate- to low-density environments, while the rest are found at the outskirts of clusters. It is likely that super spirals survive in these environments because they continue to accrete cold gas and experience only minor mergers at late times, by virtue of their enormous masses and angular momenta. We suggest that super post-mergers are the product of super spiral major mergers and may be the precursors of some giant elliptical galaxies found in low-density environments.
