- ID:
- ivo://CDS.VizieR/J/ApJ/829/78
- Title:
- Dust properties of major-merger galaxy pairs
- Short Name:
- J/ApJ/829/78
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an analysis of dust properties of a sample of close major-merger galaxy pairs selected by Ks magnitude and redshift. The pairs represent the two populations of spiral-spiral (S+S) and mixed morphology spiral-elliptical (S+E). The Code Investigating GALaxy Emission (CIGALE) software is used to fit dust models to the Two Micron All Sky Survey, Wide-Field Infrared Survey Explorer, and Herschel flux density measurements, and to derive the parameters describing the polycyclic aromatic hydrocarbons contribution, interstellar radiation field, and photodissociation regions. Model fits verify our previous Spitzer Space Telescope analysis that S+S and S+E pairs do not have the same level of enhancement of star formation and differ in dust composition.
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- ID:
- ivo://CDS.VizieR/J/A+A/565/A128
- Title:
- Dust SED in HRS nearby galaxies
- Short Name:
- J/A+A/565/A128
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Although it accounts only for a small fraction of the baryonic mass, dust has a profound impact on the physical processes at play in galaxies. Thus, to understand the evolution of galaxies, it is essential not only to characterize dust properties per se, but also in relation to global galaxy properties. To do so, we derive the dust properties of galaxies in a volume limited, K-band selected sample, the Herschel Reference Survey (HRS). We gather infrared photometric data from 8{mu}m to 500{mu}m from Spitzer, WISE, IRAS, and Herschel for all of the HRS galaxies. Draine & Li (2007ApJ...663..866D) models are fit to the data from which the stellar contribution has been carefully removed. We find that our photometric coverage is sufficient to constrain all of the parameters of the Draine & Li models and that a strong constraint on the 20-60{mu}m range is mandatory to estimate the relative contribution of the photo-dissociation regions to the infrared spectral energy distribution (SED). The SED models tend to systematically underestimate the observed 500{mu}m flux densities, especially for low-mass systems. We provide the output parameters for all of the galaxies, i.e., the minimum intensity of the interstellar radiation field, the fraction of polycyclic aromatic hydrocarbon (PAH), the relative contribution of PDR and evolved stellar population to the dust heating, the dust mass, and the infrared luminosity. For a subsample of gas-rich galaxies, we analyze the relations between these parameters and the main integrated properties of galaxies, such as stellar mass, star formation rate, infrared luminosity, metallicity, H{alpha} and H-band surface brightness, and the far-ultraviolet attenuation. A good correlation between the fraction of PAH and the metallicity is found, implying a weakening of the PAH emission in galaxies with low metallicities and, thus, low stellar masses. The intensity of the diffuse interstellar radiation field and the H-band and H{alpha} surface brightnesses are correlated, suggesting that the diffuse dust component is heated by both the young stars in star-forming regions and the diffuse evolved population. We use these results to provide a new set of infrared templates calibrated with Herschel observations on nearby galaxies and a mean SED template to provide the z=0 reference for cosmological studies. For the same purpose, we place our sample on the SFR-M_*_ diagram. The templates are compared to the most popular infrared SED libraries, enlightening a large discrepancy between all of them in the 20-100{mu}m range.
- ID:
- ivo://CDS.VizieR/J/A+A/644/A144
- Title:
- Dusty star-forming galaxies physical properties
- Short Name:
- J/A+A/644/A144
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The dust-to-stellar mass ratio (M_dust_/M*) is a crucial yet poorly constrained quantity to understand the complex physical processes involved in the production of dust, metals and stars in galaxy evolution. In this work we explore trends of M_dust_/M* with different physica parameters using observations of 300 massive, dusty star-forming galaxies detected with ALMA up to z~5. Additionally, we interpret our findings with different models of dusty galaxy formation. We find that M_dust_/M* evolves with redshift, stellar mass, specific star formation rate and integrated dust size, differently for main sequence and starburst galaxies. In both galaxy populations M_dust_/M* increases until z~2 followed by a roughly flat trend towards higher redshifts, suggesting efficient dust growth in the distant universe. We confirm that the inverse relation between M_dust_/M* and M* holds up to z~5 and can be interpreted as an evolutionary transition from early to late starburst phases. We demonstrate that M_dust_/M* in starbursts reflects the increase in molecular gas fraction with redshift, and attains the highest values for sources with the most compact dusty star-formation. The state-of-the-art cosmological simulations that include self-consistent dust growth, broadly reproduce the evolution of M_dust_/M* in main sequence galaxies, but underestimate it in starbursts. The latter is found to be linked to lower gas-phase metallicities and longer dust growth timescales relative to observations. Phenomenological models based on the main-sequence/starburst dichotomy and analytical models that include recipes for rapid metal enrichment are consistent with our observations. Therefore, our results strongly suggest that high M_dust_/M* is due to rapid dust grain growth in metal enriched interstellar medium. This work highlights multifold benefits of using M_dust_/M* as a diagnostic tool for: (1) disentangling main sequence and starburst galaxies up to z~5; (2) probing the evolutionary phase of massive objects; and (3) refining the treatment of the dust life cycle in simulations.
- ID:
- ivo://CDS.VizieR/J/ApJ/862/96
- Title:
- Dusty star-forming galaxies with LABOCA 870um obs.
- Short Name:
- J/ApJ/862/96
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present images obtained with LABOCA of a sample of 22 galaxies selected via their red Herschel SPIRE colors. We aim to see if these luminous, rare, and distant galaxies are signposting dense regions in the early universe. Our 870{mu}m survey covers an area of ~1deg^2^ down to an average rms of 3.9mJy/beam, with our five deepest maps going 2x deeper still. We catalog 86 dusty star-forming galaxies (DSFGs) around our "signposts," detected above a significance of 3.5{sigma}. This implies a 100+/-30% overdensity of S_870_>8.5mJy (or L_FIR_=6.7x10^12^-2.9x10^13^L_{sun}_) DSFGs, excluding our signposts, when comparing our number counts to those in "blank fields." Thus, we are 99.93% confident that our signposts are pinpointing overdense regions in the universe, and 95% [50%] confident that these regions are overdense by a factor of at least >=1.5x[2x]. Using template spectral energy distributions (SEDs) and SPIRE/LABOCA photometry, we derive a median photometric redshift of z=3.2+/-0.2 for our signposts, with an inter-quartile range of z=2.8-3.6, somewhat higher than expected for 850{mu}m selected galaxies. We constrain the DSFGs that are likely responsible for this overdensity to within |{delta}_z_|<=0.65 of their respective signposts. These "associated" DSFGs are radially distributed within (physical) distances of 1.6+/-0.5Mpc from their signposts, have median star formation rates (SFRs) of ~(1.0+/-0.2)x10^3^M_{sun}_/yr (for a Salpeter stellar initial mass function) and median gas reservoirs of ~1.7x10^11^M_{sun}_. These candidate protoclusters have average total SFRs of at least ~(2.3+/-0.5)x10^3^M_{sun}_/yr and space densities of 9x10^-7^Mpc^-3^, consistent with the idea that their constituents may evolve to become massive early-type galaxies in the centers of the rich galaxy clusters we see today.
- ID:
- ivo://CDS.VizieR/J/MNRAS/404/1745
- Title:
- Dwarf galaxies in Coma supercluster
- Short Name:
- J/MNRAS/404/1745
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyse Spitzer Multiband Imaging Photometer (MIPS) 24um observations, and Sloan Digital Sky Survey Data Release 7 optical broad-band photometry and spectra, to investigate the star formation (SF) properties of galaxies residing in the Coma supercluster region. We find that SF in dwarf galaxies is quenched only in the high-density environment at the centre of clusters and groups, but that passively evolving massive galaxies are found in all environments, indicating that massive galaxies can become passive via internal processes. The SF-density relation observed for the massive galaxies is weaker relative to the dwarfs, but both show a trend for the fraction of star-forming galaxies (f_SF_) declining to ~0 in the cluster cores. We find that active galactic nucleus activity is also suppressed among massive galaxies residing in the cluster cores.
- ID:
- ivo://CDS.VizieR/J/ApJ/813/L15
- Title:
- Dwarf galaxies in Fornax cluster from NGFS
- Short Name:
- J/ApJ/813/L15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of 158 previously undetected dwarf galaxies in the Fornax cluster central regions using a deep coadded u-, g-, and i-band image obtained with the Dark Energy Camera wide-field camera mounted on the 4-m Blanco telescope at the Cerro Tololo Interamerican Observatory as part of the Next Generation Fornax Survey (NGFS). The new dwarf galaxies have quasi-exponential light profiles, effective radii 0.1<r_e_<2.8kpc, and average effective surface brightness values 22.0<{mu}_i_<28.0mag/arcsec2. We confirm the existence of ultra-diffuse galaxies (UDGs) in the Fornax core regions that resemble counterparts recently discovered in the Virgo and Coma galaxy clusters. We also find extremely low surface brightness NGFS dwarfs, which are several magnitudes fainter than the classical UDGs. The faintest dwarf candidate in our NGFS sample has an absolute magnitude of M_i_=-8.0mag. The nucleation fraction of the NGFS dwarf galaxy sample appears to decrease as a function of their total luminosity, reaching from a nucleation fraction of >75% at luminosities brighter than M_i_~=-15.0mag to 0% at luminosities fainter than M_i_~=-10.0mag. The two-point correlation function analysis of the NGFS dwarf sample shows an excess on length scales below ~100 kpc, pointing to the clustering of dwarf galaxies in the Fornax cluster core.
- ID:
- ivo://CDS.VizieR/J/MNRAS/369/1375
- Title:
- Dwarf galaxies in NGC 1407 Group
- Short Name:
- J/MNRAS/369/1375
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The NGC 1407 Group stands out among nearby structures by its properties that suggest it is massive and evolved. It shares properties with entities that have been called fossil groups: the 1.4m differential between the dominant elliptical galaxy and the second brightest galaxy comes close to satisfying the definition that has been used to define the fossil class. There are few intermediate-luminosity galaxies, but a large number of dwarfs in the group. We estimate there are 250 group members to the depth of our survey. The slope of the faint end of the luminosity function (reaching M_R_=12) is alpha=-1.35. Velocities for 35 galaxies demonstrate that this group with one dominant galaxy has a mass of 7x10^13^M_{sun}_ and M/L_R_=340M_{sun}_/L_{sun}_. Two galaxies in close proximity to NGC 1407 have very large blueshifts. The most notable is the second brightest galaxy, NGC 1400, with a velocity of 1072km/s with respect to the group mean. We report the detection of X-ray emission from this galaxy and from the group.
- ID:
- ivo://CDS.VizieR/J/AJ/133/715
- Title:
- Dwarf galaxies of the Local Group
- Short Name:
- J/AJ/133/715
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of an all-sky, deep optical survey for faint Local Group dwarf galaxies. Candidate objects were selected from the second Palomar Observatory Sky Survey and ESO/Science Research Council survey plates, and follow-up observations were performed to determine whether they were indeed overlooked members of the Local Group. Only two galaxies (Antlia and Cetus) were discovered this way out of 206 candidates. Based on internal and external comparisons, we estimate that our visual survey is more than 77% complete for objects larger than 1' in size and with a surface brightness greater than an extremely faint limit over the 72% of the sky not obstructed by the Milky Way.
- ID:
- ivo://CDS.VizieR/J/AJ/146/104
- Title:
- Dwarf galaxies surface brightness profiles. I.
- Short Name:
- J/AJ/146/104
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Radial surface brightness profiles of spiral galaxies are classified into three types: (I) single exponential, or the light falls off with one exponential to a break before falling off (II) more steeply, or (III) less steeply. Profile breaks are also found in dwarf disks, but some dwarf Type IIs are flat or increasing out to a break before falling off. Here we re-examine the stellar disk profiles of 141 dwarfs: 96 dwarf irregulars (dIms), 26 Blue Compact Dwarfs (BCDs), and 19 Magellanic-type spirals (Sms). We fit single, double, or even triple exponential profiles in up to 11 passbands: GALEX FUV and NUV, ground-based UBVJHK and H{alpha}, and Spitzer 3.6 and 4.5{mu}m. We find that more luminous galaxies have brighter centers, larger inner and outer scale lengths, and breaks at larger radii; dwarf trends with M_B_extend to spirals. However, the V-band break surface brightness is independent of break type, M_B_, and Hubble type. Dwarf Type II and III profiles fall off similarly beyond the breaks but have different interiors and IIs break ~twice as far as IIIs. Outer Type II and III scale lengths may have weak trends with wavelength, but pure Type II inner scale lengths clearly decrease from the FUV to visible bands whereas Type III inner scale lengths increase with redder bands. This suggests the influence of different star formation histories on profile type, but nonetheless the break location is approximately the same in all passbands. Dwarfs continue trends between profile and Hubble types such that later-type galaxies have more Type II but fewer Type I and III profiles than early-type spirals. BCDs and Sms are over-represented as Types III and II, respectively, compared to dIms.
- ID:
- ivo://CDS.VizieR/J/AJ/151/145
- Title:
- Dwarf galaxies surface brightness profiles. II.
- Short Name:
- J/AJ/151/145
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this second paper of a series, we explore the B-V, U-B, and FUV-NUV radial color trends from a multi-wavelength sample of 141 dwarf disk galaxies. Like spirals, dwarf galaxies have three types of radial surface brightness profiles: (I) single exponential throughout the observed extent (the minority), (II) down-bending (the majority), and (III) up-bending. We find that the colors of (1) Type I dwarfs generally become redder with increasing radius, unlike spirals which have a blueing trend that flattens beyond ~1.5 disk scale lengths, (2) Type II dwarfs come in six different "flavors", one of which mimics the "U" shape of spirals, and (3) Type III dwarfs have a stretched "S" shape where the central colors are flattish, become steeply redder toward the surface brightness break, then remain roughly constant beyond, which is similar to spiral Type III color profiles, but without the central outward bluing. Faint (-9>M_B_>-14) Type II dwarfs tend to have continuously red or "U" shaped colors and steeper color slopes than bright (-14>M_B_>-19) Type II dwarfs, which additionally have colors that become bluer or remain constant with increasing radius. Sm dwarfs and BCDs tend to have at least some blue and red radial color trend, respectively. Additionally, we determine stellar surface mass density ({Sigma}) profiles and use them to show that the break in {Sigma} generally remains in Type II dwarfs (unlike Type II spirals) but generally disappears in Type III dwarfs (unlike Type III spirals). Moreover, the break in {Sigma} is strong, intermediate, and weak in faint dwarfs, bright dwarfs, and spirals, respectively, indicating that {Sigma} may straighten with increasing galaxy mass. Finally, the average stellar surface mass density at the surface brightness break is roughly 1-2M_{Sun}_pc^-2^ for Type II dwarfs but higher at 5.9M_{Sun}_pc^-2^ or 27M_{Sun}_pc^-2^ for Type III BCDs and dIms, respectively.