- 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.
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- 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.
- ID:
- ivo://CDS.VizieR/J/A+A/627/A6
- Title:
- APEX spectra of Centaurus A
- Short Name:
- J/A+A/627/A6
- 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. Optical filaments located at 16 kpc from the galaxy along the radio jet direction show recent star formation, likely triggered by the interaction of the jet with an HI shell. A large reservoir of molecular gas has been discovered outside the HI. In this reservoir, lies the Horseshoe complex: a filamentary structure seen in CO with ALMA and in Halpha with MUSE. The ionised gas is mostly excited by shocks, with only a minor contribution of star formation. We used the Atacama Pathfinder EXperiment (APEX) to observe the ^12^CO(3-2) and ^12^CO(4-3) transitions, as well as dense gas tracers in the Horseshoe complex. ^12^CO(3-2) and ^12^CO(4-3) are detected for the first time in the northern filaments of Centaurus A, with integrated intensity line ratios R32~0.2 and R43~0.1, compared to the ^12^CO(1-0) emission. We also derived a line ratio R21~0.6, based on the previous ^12^CO(2-1) observations of Salome et al. (2016, Cat. J/A+A/595/A65). We used the non-LTE radiative transfer code RADEX and determined that the molecular gas in this region has a temperature of 55-70K and densities between 2-6x10^2^cm^-3^. Such densities are also in agreement with results from the Paris-Durham shock code that predicts a post-shock density of a few 100cm^-3^. However, we need more observations of emission lines at a better angular resolution in order to place tighter constraints on our radiative models, whether they are used as a stand-alone tool (LVG codes) or combined with a shock model.
- ID:
- ivo://CDS.VizieR/J/A+A/595/A65
- Title:
- APEX spectra of Centaurus A
- Short Name:
- J/A+A/595/A65
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- NGC 5128 (Centaurus A) is one of the best example to study AGN-feedback in the local Universe. At 13.5kpc from the galaxy, optical filaments with recent star formation are lying along the radio-jet direction. We used the Atacama Pathfinder EXperiment (APEX) to map the CO(2-1) emission all along the filaments structure. Molecular gas mass of 8.2x10^7M_{sun}_ was found over the 4.2kpc-structure which represents about 3% of the total gas mass of the NGC 5128 cold gas content. Two dusty mostly molecular structures are identified, following the optical filaments. The region corresponds to the crossing of the radio jet with the northern HI shell, coming from a past galaxy merger. One filament is located at the border of the HI shell, while the other is entirely molecular, and devoid of HI gas. The molecular mass is comparable to the HI mass in the shell, suggesting a scenario where the atomic gas was shocked and transformed in molecular clouds by the radio jet. Comparison with combined FIR Herschel and UV GALEX estimation of star formation rates in the same regions leads to depletion times of more than 10 Gyr. The filaments are thus less efficient than discs in converting molecular gas into stars. Kinetic energy injection triggered by shocks all along the jet/gas interface is a possible process that appears to be consistent with MUSE line ratio diagnostics derived in a smaller region of the northern filaments. Whether the AGN is the sole origin of this energy input and what is the dominant (mechanical vs radiative) mode for this process is however still to be investigated.
- ID:
- ivo://CDS.VizieR/J/AJ/110/1032
- Title:
- APM elliptical galaxies radial velocities
- Short Name:
- J/AJ/110/1032
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 292 new redshifts of elliptical galaxies selected from the APM Bright Galaxy Survey. We use these data together with published redshifts and bj apparent magnitudes from the APM Bright Galaxy Survey in order to estimate the shape of the Luminosity Function of a total sample of 535 ellipticals. We use the Maximum Likelihood method for the determination of the best fitting parameters {alpha} and M^*^ of a Schechter Function. In order to provide tests for systematics and suitable error estimates we apply Monte Carlo techniques which are also used to deal with incompleteness effects in the data. In agreement with other authors our results indicate a relative lack of low luminosity ellipticals compared to other morphological types. The best fitting shape parameters derived are {alpha}=0.20+/-0.25 and M^*^_Bj_=-20.0+/-0.3. We do not find evidence for a dependence of these parameters on environment.
- ID:
- ivo://CDS.VizieR/J/ApJ/473/822
- Title:
- APS Catalog of Galaxies behind Virgo
- Short Name:
- J/ApJ/473/822
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of 1268 galaxies, essentially complete to B<=17.0, found by scanning glass copies of several fields of the original Palomar Sky Survey using the Minnesota Automated Plate Scanner in its isodensitometric mode (as opposed to the threshold densitometric mode used in the APS Catalog of the POSS I). In addition to the different scanning mode, we have employed a different star-galaxy separation method and have visually inspected POSS prints to verify that each image remaining in the catalog is non-stellar. The scanned fields are distributed generally in two areas, one around the outskirts of the Virgo Cluster, the other toward the antipode of the cluster (but still in the northern celestial hemisphere). The catalog gives the position of the center of each galaxy; estimates of the blue and red magnitudes within the outermost threshold crossing and of the blue magnitude extrapolated to zero surface brightness; blue and red diameters of four ellipses fit to the four threshold crossings (approximately 23.8, 23.6, 23.2, and 22.7 mag per square arcsec in blue, and 22.5, 22.4, 21.5 and 21.2 mag per square arcsec in red), and the ellipticities of those four ellipses. The catalog has served as a base from which to draw targets for a Tully-Fisher study of the Virgocentric infall velocity of the Local Group.
- ID:
- ivo://CDS.VizieR/VII/214
- Title:
- APS Galaxies in the North Galactic Pole
- Short Name:
- VII/214
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (of PhD Thesis, from Minessota) I am using the Minnesota Automated Plate Scanner (APS) to construct two galaxy catalogs. The Minnesota Automated Plate Scanner Pisces-Perseus Survey (MAPS-PP) is used to search for modern-day remnant signatures of large-scale structure formation processes, specifically, galaxy alignments relative to surrounding large-scale structure. Weak evidence for such alignments is found, although the type of alignments seen don't strongly support any one large-scale structure formation model. Comparison of the MAPS-PP to pre-existing galaxy catalogs has led to the discovery that the Uppsala General Catalog and Third Reference Catalog of Galaxies exhibit a very strong measurement bias: their diameters are measured to different isophotes at different galaxy inclinations. Therefore previous determinations of the diameter function and the internal extinction properties of other galaxies (most of which have relied on one of these two galaxy catalogs) have suffered from a biased diameter measurement. I avoid this bias by using the APS data (which is obtained using automated computer-based criteria for measuring the structural properties of images digitized from photographic plates) to construct a catalog of over 200,000 galaxies within 30 degrees of the North Galactic Pole (the MAPS-NGP). The MAPS-NGP is the deepest galaxy catalog constructed over such a large area of the sky and used to re-evaluate previous investigations of the internal extinction in galaxies.
