- ID:
- ivo://CDS.VizieR/J/A+A/651/L15
- Title:
- Angular-momentum plane for disc galaxies
- Short Name:
- J/A+A/651/L15
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- The relations between the specific angular momenta (j) and masses (M) of galaxies are often used as a benchmark in analytic models and hydrodynamical simulations as they are considered to be amongst the most fundamental scaling relations. Using accurate measurements of the stellar (j*), gas (jgas), and baryonic (jbar) specific angular momenta for a large sample of disc galaxies, we report the discovery of tight correlations between j, M, and the cold gas fraction of the interstellar medium (fgas). At fixed fgas, galaxies follow parallel power laws in 2D (j, M) spaces, with gas-rich galaxies having a larger j* and jbar (but a lower jgas) than gas-poor ones. The slopes of the relations have a value around 0.7. These new relations are amongst the tightest known scaling laws for galaxies. In particular, the baryonic relation (jbar-Mbar-fgas), arguably the most fundamental of the three, is followed not only by typical discs but also by galaxies with extreme properties, such as size and gas content, and by galaxies previously claimed to be outliers of the standard 2D j-M relations. The stellar relation (j*-M*-fgas) may be connected to the known j*-M* bulge fraction relation; however, we argue that the jbar-Mbar-fgas relation can originate from the radial variation in the star formation efficiency in galaxies, although it is not explained by current disc instability models.
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- ID:
- ivo://CDS.VizieR/J/MNRAS/452/4274
- Title:
- Angular sizes of AGN cores at 2-43GHz
- Short Name:
- J/MNRAS/452/4274
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have measured the angular sizes of radio cores of active galactic nuclei (AGN) and analyzed their sky distributions and frequency dependencies to study synchrotron opacity in AGN jets and the strength of angular broadening in the interstellar medium. We have used archival very long baseline interferometry (VLBI) data of more than 3000 compact extragalactic radio sources observed at frequencies, {nu}, from 2 to 43GHz to measure the observed angular size of VLBI cores. We have found a significant increase in the angular sizes of the extragalactic sources seen through the Galactic plane (|b|<10{deg}) at 2, 5 and 8GHz, about 1/3 of which show significant scattering. These sources are mainly detected in directions to the Galactic bar, the Cygnus region, and a region with galactic longitudes 220{deg}<l<260{deg} (the Fitzgerald window). The strength of interstellar scattering of the AGNs is found to correlate with the Galactic H{alpha} intensity, free-electron density, and Galactic rotation measure. The dependence of scattering strengths on source redshift is insignificant, suggesting that the dominant scattering screens are located in our Galaxy. The observed angular size of Sgr-A* is found to be the largest among thousands of AGN observed over the sky; we discuss possible reasons of this strange result. Excluding extragalactic radio sources with significant scattering, we find that angular size of opaque cores in AGN scales typically as {nu}^-1^ confirming predictions of a conical synchrotron jet model with equipartition.
- ID:
- ivo://CDS.VizieR/J/MNRAS/437/3883
- Title:
- A non-parametric method for galaxy morphology
- Short Name:
- J/MNRAS/437/3883
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a non-parametric cell-based method of selecting highly pure and largely complete samples of spiral galaxies using photometric and structural parameters as provided by standard photometric pipelines and simple shape fitting algorithms. The performance of the method is quantified for different parameter combinations, using purely human-based classifications as a benchmark. The discretization of the parameter space allows a markedly superior selection than commonly used proxies relying on a fixed curve or surface of separation. Moreover, we find structural parameters derived using passbands longwards of the g band and linked to older stellar populations, especially the stellar mass surface density mu_*_ and the r band effective radius r_e_, to perform at least equally well as parameters more traditionally linked to the identification of spirals by means of their young stellar populations, e.g. UV/optical colours. In particular the distinct bimodality in the parameter mu_*_, consistent with expectations of different evolutionary paths for spirals and ellipticals, represents an often overlooked yet powerful parameter in differentiating between spiral and non-spiral/elliptical galaxies. We use the cell-based method for the optical parameter set including r_e_ in combination with the Sersic index n and the i-band magnitude to investigate the intrinsic specific star-formation rate - stellar mass relation ({psi}_*_-M_*_) for a morphologically defined volume limited sample of local universe spiral galaxies. The relation is found to be well described by {psi}_*_{propto}M_*_^-0.5^ over the range of 10^9.5^M_{sun}_<=M_*_<=10^11^M_{sun}_ with a mean interquartile range of 0.4dex. This is somewhat steeper than previous determinations based on colour-selected samples of star-forming galaxies, primarily due to the inclusion in the sample of red quiescent disks.
- ID:
- ivo://CDS.VizieR/VIII/3
- Title:
- An Optical Catalogue of Radio Galaxies
- Short Name:
- VIII/3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog contains basic optical information on all known radio galaxies (with L[radio] greater than about 10**[41] ergs/s) that had been identified as of 1979 and for which measured redshifts were available. The data include the right ascension and declination (1950); galaxy (optical) type; visual magnitude; photoelectric colors; redshift (z) and the spectral lines on which the redshift measurements were based; coordinate designations; radio flux and frequency; radio spectral index; other names; and the references for the galaxy identification, photometric data, redshift, radio flux, radio spectral index, and radio map number. Note that the ADC version of this catalog differs somewhat from the original printed catalog in that some fields were added or modified and other fields reordered. In addition to the catalog data file itself, two additional files containing the list of references for the catalog are also available. The first reference list is in alphabetical order, and the second is in numerical order.
- ID:
- ivo://CDS.VizieR/J/AJ/140/75
- Title:
- Antennae galaxies (NGC 4038/4039) revisited
- Short Name:
- J/AJ/140/75
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Advanced Camera for Surveys and the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) have been used to obtain new Hubble Space Telescope images of NGC 4038/4039 ("The Antennae"). These new observations allow us to better differentiate compact star clusters from individual stars, based on both size and color.
- ID:
- ivo://CDS.VizieR/III/157
- Title:
- An Ultraviolet Atlas of Quasar and Blazar Spectra
- Short Name:
- III/157
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This atlas contains the ultraviolet spectra of 70 quasars, blazars, and Seyfert 1 galaxies that were produced by combining over 100 low resolution spectra from the International Ultraviolet Explorer (IUE) data archive. The spectra have been extracted with an optimal algorithm (see Kinney et al. 1991) and co-added to produce spectra with the best possible signal-to-noise ratio.
- ID:
- ivo://CDS.VizieR/J/ApJ/725/200
- Title:
- An updated catalog of M31 globular-like clusters
- Short Name:
- J/ApJ/725/200
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an updated UBVRI photometric catalog containing 970 objects in the field of M31, selected from the Revised Bologna Catalog (RBC v.4.0), including 965, 967, 965, 953, and 827 sources in the individual UBVRI bands, respectively, of which 205, 123, 14, 126, and 109 objects do not have previously published photometry. Photometry is performed using archival images from the Local Group Galaxies Survey, which covers 2.2deg^2^ along the major axis of M31. Detailed comparisons show that our photometry is fully consistent with previous measurements in all filters. We focus on 445 confirmed "globular-like" clusters and candidates, comprising typical globular and young massive clusters. The ages and masses of these objects are derived by comparing their observed spectral-energy distributions with simple stellar population synthesis. Approximately half of the clusters are younger than 2Gyr, suggesting that there has been significant recent active star formation in M31, which is consistent with previous results.
- ID:
- ivo://CDS.VizieR/J/A+A/434/483
- Title:
- An XMM-Newton survey of M 31
- Short Name:
- J/A+A/434/483
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In an analysis of XMM archival observations of the bright Local Group spiral galaxy M 31 we study the population of X-ray sources (X-ray binaries, supernova remnants) down to a 0.2-4.5keV luminosity of 4.4x10^34^erg/s. EPIC hardness ratios and optical and radio information are used to distinguish between different source classes. The survey detects 856 sources in an area of 1.24 square degrees. We correlate our sources with earlier M 31 X-ray catalogues and use information from optical, infra-red and radio wavelengths. As sources within M 31 we detect 21 supernova remnants (SNR) and 23 SNR candidates, 18 supersoft source (SSS) candidates, 7 X-ray binaries (XRBs) and 9 XRB candidates, as well as 27 globular cluster sources (GlC) and 10 GlC candidates, which most likely are low mass XRBs within the GlC. Comparison to earlier X-ray surveys reveal transients not detected with XMM-Newton, which add to the number of M 31 XRBs. There are 567 sources classified as hard, which may either be XRBs or Crab-like SNRs in M 31 or background AGN. The number of 44 SNRs and candidates more than doubles the X-ray-detected SNRs. 22 sources are new SNR candidates in M 31 based on X-ray selection criteria. Another SNR candidate may be the first plerion detected outside the Galaxy and the Magellanic Clouds. On the other hand, six sources are foreground stars and 90 foreground star candidates, one is a BL Lac-type active galactic nucleus (AGN) and 36 are AGN candidates, one source coincides with the Local Group galaxy M 32, one with a background galaxy cluster (GCl) and another is a GCl candidate, all sources not connected to M31.
- ID:
- ivo://CDS.VizieR/J/ApJS/80/531
- Title:
- An X-ray catalog and atlas of galaxies.
- Short Name:
- J/ApJS/80/531
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An X-ray catalog and atlas of galaxies observed with the Einstein Observatory imaging instruments (IPC and HRI) are presented. The catalog comprises 493 galaxies, including targets of pointed observations, and RSA or RC2 galaxies serendipitously included in Einstein fields. A total of 450 of these galaxies were imaged well within the instrumental fields, resulting in 238 detections and 2123 sigma upper limits. The other galaxies were either at the edge of the visible field of view or confused with other X-ray sources. For these a rough measure of their X-ray emission is also given. The atlas shows X-ray contour maps of detected galaxies superposed on optical photographs and gives azimuthally averaged surface brightness profiles of galaxies detected with a high signal-to-noise ratio.
- ID:
- ivo://CDS.VizieR/J/ApJ/727/83
- Title:
- A panchromatic study of BLAST counterparts
- Short Name:
- J/ApJ/727/83
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We carry out a multi-wavelength study of individual galaxies detected by the Balloon-borne Large Aperture Submillimeter Telescope (BLAST) and identified at other wavelengths, using data spanning the radio to the ultraviolet (UV). We develop a Monte Carlo method to account for flux boosting, source blending, and correlations among bands, which we use to derive deboosted far-infrared (FIR) luminosities for our sample. We estimate total star-formation rates (SFRs) for BLAST counterparts with z<=0.9 by combining their FIR and UV luminosities. We assess that about 20% of the galaxies in our sample show indication of a type 1 active galactic nucleus, but their submillimeter emission is mainly due to star formation in the host galaxy. We compute stellar masses for a subset of 92 BLAST counterparts; these are relatively massive objects, with a median mass of ~10^11^M_{sun}_, which seem to link the 24um and Submillimetre Common-User Bolometer Array (SCUBA) populations, in terms of both stellar mass and star formation activity.
