- ID:
- ivo://CDS.VizieR/J/ApJ/809/20
- Title:
- The M_BH_-{sigma} relation for active galaxies
- Short Name:
- J/ApJ/809/20
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We create a baseline of the black hole (BH) mass (M_BH_)-stellar-velocity dispersion ({sigma}) relation for active galaxies, using a sample of 66 local (0.02<z<0.09) Seyfert-1 galaxies, selected from the Sloan Digital Sky Survey (SDSS). Analysis of SDSS images yields AGN luminosities free of host-galaxy contamination, and morphological classification. 51/66 galaxies have spiral morphology. Out of these, 28 bulges have Sersic index n<2 and are considered candidate pseudo-bulges, with eight being definite pseudo-bulges based on multiple classification criteria met. Only 4/66 galaxies show signs of interaction/merging. High signal-to-noise ratio Keck spectra provide the width of the broad H{beta} emission line free of Fe II emission and stellar absorption. AGN luminosity and H{beta} line widths are used to estimate M_BH_. The Keck-based spatially resolved kinematics is used to determine stellar-velocity dispersion within the spheroid effective radius ({sigma}_spat,reff_). We find that {sigma} can vary on average by up to 40% across definitions commonly used in the literature, emphasizing the importance of using self-consistent definitions in comparisons and evolutionary studies. The M_BH_-{sigma} relation for our Seyfert-1 galaxy sample has the same intercept and scatter as that of reverberation-mapped AGNs as well as that of quiescent galaxies, consistent with the hypothesis that our single epoch M_BH_ estimator and sample selection function do not introduce significant biases. Barred galaxies, merging galaxies, and those hosting pseudo-bulges do not represent outliers in the M_BH_-{sigma} relation. This is in contrast with previous work, although no firm conclusion can be drawn on this matter due to the small sample size and limited resolution of the SDSS images.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/727/20
- Title:
- The Megamaser Cosmology Project (MCP). III.
- Short Name:
- J/ApJ/727/20
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Observations of H_2_O masers from circumnuclear disks in active galaxies for the Megamaser Cosmology Project (MCP) allow accurate measurement of the mass of supermassive black holes (BH) in these galaxies. We present the Very Long Baseline Interferometry images and kinematics of water maser emission in six active galaxies: NGC 1194, NGC 2273, NGC 2960 (Mrk 1419), NGC 4388, NGC 6264 and NGC 6323. We use the Keplerian rotation curves of these six megamaser galaxies, plus a seventh previously published, to determine accurate enclosed masses within the central ~0.3pc of these galaxies, smaller than the radius of the sphere of influence of the central mass in all cases.
- ID:
- ivo://CDS.VizieR/J/MNRAS/416/2840
- Title:
- The 2M++ galaxy redshift catalogue
- Short Name:
- J/MNRAS/416/2840
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Peculiar velocities arise from gravitational instability, and thus are linked to the surrounding distribution of matter. In order to understand the motion of the Local Group with respect to the cosmic microwave background, a deep all-sky map of the galaxy distribution is required. Here we present a new redshift compilation of 69160 galaxies, dubbed 2M++, to map large-scale structures of the local Universe over nearly the whole sky, and reaching depths of K<=12.5, or 200h^-1^Mpc. The target catalogue is based on the Two-Micron All-Sky Survey Extended Source Catalog (2MASS-XSC). The primary sources of redshifts are the 2MASS Redshift Survey, the 6dF galaxy redshift survey and the Sloan Digital Sky Survey (Data Release 7). We assess redshift completeness in each region and compute the weights required to correct for redshift incompleteness and apparent magnitude limits, and discuss corrections for incompleteness in the zone of avoidance. We present the density field for this survey, and discuss the importance of large-scale structures such as the Shapley Concentration.
- 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.
- 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.
