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- 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.
- ID:
- ivo://CDS.VizieR/J/A+A/659/A89
- Title:
- Aperture-corrected SN Ia host properties
- Short Name:
- J/A+A/659/A89
- Date:
- 11 Mar 2022 07:19:46
- Publisher:
- CDS
- Description:
- We use type Ia supernova (SN Ia) data obtained by the Sloan Digital Sky Survey-II Supernova Survey (SDSS-II SNS) in combination with the publicly available SDSS DR16 fiber spectroscopy of supernova (SN) host galaxies to correlate SN Ia light-curve parameters and Hubble residuals with several host galaxy properties. Fixed-aperture fiber spectroscopy suffers from aperture effects: the fraction of the galaxy covered by the fiber varies depending on its projected size on the sky, and thus measured properties are not representative of the whole galaxy. The advent of integral field spectroscopy has provided a way to correct the missing light, by studying how these galaxy parameters change with the aperture size. Here we study how the standard SN host galaxy relations change once global host galaxy parameters are corrected for aperture effects. We recover previous trends on SN Hubble residuals with host galaxy properties, but we find that discarding objects with poor fiber coverage instead of correcting for aperture loss introduces biases into the sample that affect SN host galaxy relations. The net effect of applying the commonly used g-band fraction criterion is that intrinsically faint SNe Ia in high-mass galaxies are discarded, thus artificially increasing the height of the mass step by 0.02 mag and its significance. Current and next-generation fixed-aperture fiber-spectroscopy surveys, such as DES, DESI, or TiDES in 4MOST, that aim to study SN and galaxy correlations must consider, and correct for, these effects.
- ID:
- ivo://CDS.VizieR/J/ApJ/671/333
- Title:
- Aperture photometry in NGC 5194
- Short Name:
- J/ApJ/671/333
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have studied the relationship between the star formation rate (SFR), surface density, and gas surface density in the spiral galaxy M51a (NGC 5194), using multiwavelength data obtained as part of the Spitzer Infrared Nearby Galaxies Survey (SINGS). We introduce a new SFR index based on a linear combination of Halpha emission-line and 24um continuum luminosities, which provides reliable extinction-corrected ionizing fluxes and SFR densities over a wide range of dust attenuations.
- ID:
- ivo://CDS.VizieR/J/A+A/654/A6
- Title:
- Aperture photometry of the M31 PHAT clusters
- Short Name:
- J/A+A/654/A6
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- This study is the sixth of a series that investigates degeneracy and stochasticity problems present in the determination of the age, mass, extinction, and metallicity of partially resolved or unresolved star clusters in external galaxies when using Hubble Space Telescope broadband photometry. In the fifth publication, it was noticed that inconsistencies in cluster colour indices, which arise due to projected foreground and background stars on the apertures, enhance age-metallicity-extinction degeneracies. In this work we aim to present new aperture photometry results for a sample of star clusters from the M31 Panchromatic Hubble Andromeda Treasury (PHAT) survey. We employed two methods of aperture photometry. The first method is ordinary aperture photometry to measure total cluster fluxes. The second method was introduced to avoid the brightest foreground and background stars that project onto large apertures. This method employs smaller apertures, adapted to cover a central part of clusters, and applies an aperture correction, derived for the F475W passband, to other passbands.We note that this procedure is valid only for clusters without prominent systematic gradients of colour indices beyond half-light radii. We present two catalogues of star cluster aperture photometry (produced by applying ordinary aperture photometry and adaptive aperture photometry methods) with estimated uncertainties for a sample of 1181 star clusters from the M31 PHAT survey. Compared to the M31 PHAT fundamental star cluster aperture photometry catalogue published by Johnson et al., there are changes made in the following: cluster centre coordinates, aperture sizes, and sky background estimates.
- ID:
- ivo://CDS.VizieR/J/A+A/608/A98
- Title:
- APEX spectra of Centaurus A
- Short Name:
- J/A+A/608/A98
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- NGC 5128 (Centaurus A) is one of the best targets to study AGN feedback in the local Universe. At 13.5kpc from the galaxy, optical filaments with recent star formation lie along the radio jet direction. This region is a testbed for positive feedback, here through jet-induced star formation. Atacama Pathfinder EXperiment (APEX) observations have revealed strong CO emission in star-forming regions and in regions with no detected tracers of star formation activity. In cases where star formation is observed, this activity appears to be inefficient compared to the Kennicutt-Schmidt relation. We used the Atacama Large Millimeter/submillimeter Array (ALMA) to map the 12CO(1-0) emission all along the filaments of NGC 5128 at a resolution of 1.3"~23.8pc. We find that the CO emission is clumpy and is distributed in two main structures: (i) the Horseshoe complex, located outside the HI cloud, where gas is mostly excited by shocks and where no star formation is observed, and (ii) the Vertical filament, located at the edge of the HI shell, which is a region of moderate star formation. We identified 140 molecular clouds using a clustering method applied to the CO data cube. A statistical study reveals that these clouds have very similar physical properties, such as size, velocity dispersion, and mass, as in the inner Milky Way. However, the range of radius available with the present ALMA observations does not enable us to investigate whether or not the clouds follow the Larson relation. The large virial parameter {alpha}_vir_ of the clouds suggests that gravity is not dominant and clouds are not gravitationally unstable. Finally, the total energy injection in the northern filaments of Centaurus A is of the same order as in the inner part of the Milky Way. The strong CO emission detected in the northern filaments is an indication that the energy injected by the jet acts positively in the formation of dense molecular gas. The relatively high virial parameter of the molecular clouds suggests that the injected kinetic energy is too strong for star formation to be efficient. This is particularly the case in the Horseshoe complex, where the virial parameter is the largest and where strong CO is detected with no associated star formation. This is the first evidence of AGN positive feedback in the sense of forming molecular gas through shocks, associated with low star formation efficiency due to turbulence injection by the interaction with the radio jet.
