- ID:
- ivo://CDS.VizieR/J/ApJ/744/150
- Title:
- Dust-obscured galaxies (DOGs) at z=~2
- Short Name:
- J/ApJ/744/150
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Spitzer Space Telescope has identified a population of ultraluminous infrared galaxies (ULIRGs) at z~2 that may play an important role in the evolution of massive galaxies. We measure the stellar masses (M_*_) of two populations of Spitzer-selected ULIRGs that have extremely red R-[24] colors (dust-obscured galaxies, or DOGs) and compare our results with submillimeter-selected galaxies (SMGs). One set of 39 DOGs has a local maximum in their mid-infrared (mid-IR) spectral energy distribution (SED) at rest frame 1.6um associated with stellar emission ("bump DOGs"), while the other set of 51 DOGs have power-law mid-IR SEDs that are typical of obscured active galactic nuclei ("power-law DOGs"). We measure M_*_ by applying Charlot & Bruzual (1991ApJ...367..126C) stellar population synthesis models to broadband photometry in the rest-frame ultraviolet, optical, and near-infrared of each of these populations.
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- ID:
- ivo://CDS.VizieR/J/ApJ/769/116
- Title:
- Dust-obscured galaxies in the local universe
- Short Name:
- J/ApJ/769/116
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use Wide-field Infrared Survey Explorer (WISE), AKARI, and Galaxy Evolution Explorer (GALEX) data to select local analogs of high-redshift (z~2) dust obscured galaxies (DOGs). We identify 47 local DOGs with S_12{mu}m_/S_0.22{mu}m_>=892 and S_12{mu}m_>20mJy at 0.05<z<0.08 in the Sloan Digital Sky Survey data release 7. The infrared (IR) luminosities of these DOGs are in the range 3.4x10^10^(L_{sun}_)<~L_IR_<~7.0x10^11^(L_{sun}_) with a median L_IR_ of 2.1x10^11^(L_{sun}_). We compare the physical properties of local DOGs with a control sample of galaxies that have lower S_12{mu}m_/S_0.22{mu}m_ but have similar redshift, IR luminosity, and stellar mass distributions. Both WISE 12{mu}m and GALEX near-ultraviolet (NUV) flux densities of DOGs differ from the control sample of galaxies, but the difference is much larger in the NUV. Among the 47 DOGs, 36%+/-7% have small axis ratios in the optical (i.e., b/a<0.6), larger than the fraction among the control sample (17%+/-3%). There is no obvious sign of interaction for many local DOGs. No local DOGs have companions with comparable optical magnitudes closer than ~50kpc. The large- and small-scale environments of DOGs are similar to the control sample. Many physical properties of local DOGs are similar to those of high-z DOGs, even though the IR luminosities of local objects are an order of magnitude lower than for the high-z objects: the presence of two classes (active galactic nuclei- and star formation-dominated) of DOGs, abnormal faintness in the UV rather than extreme brightness in the mid-IR, and diverse optical morphology. These results suggest a common underlying physical origin of local and high-z DOGs. Both seem to represent the high-end tail of the dust obscuration distribution resulting from various physical mechanisms rather than a unique phase of galaxy evolution.
- ID:
- ivo://CDS.VizieR/J/A+A/582/A121
- Title:
- Dust properties in galaxies
- Short Name:
- J/A+A/582/A121
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this work, we aim to provide a consistent analysis of the dust properties from metal-poor to metal-rich environments by linking them to fundamental galactic parameters. We consider two samples of galaxies: the Dwarf Galaxy Survey (DGS) and the Key Insights on Nearby Galaxies: a Far-Infrared Survey with Herschel (KINGFISH), totalling 109 galaxies, spanning almost 2dex in metallicity. We collect infrared (IR) to submillimetre (submm) data for both samples and present the complete data set for the DGS sample. We model the observed spectral energy distributions (SED) with a physically-motivated dust model to access the dust properties: dust mass, total-IR luminosity, polycyclic aromatic hydrocarbon (PAH) mass fraction, dust temperature distribution, and dust-to-stellar mass ratio. Using a different SED model (modified black body), different dust composition (amorphous carbon in lieu of graphite), or a different wavelength coverage at submm wavelengths results in differences in the dust mass estimate of a factor two to three, showing that this parameter is subject to non-negligible systematic modelling uncertainties. We find half as much dust with the amorphous carbon dust composition. For eight galaxies in our sample, we find a rather small excess at 500{mu}m (<=1.5{sigma}). We find that the dust SED of low-metallicity galaxies is broader and peaks at shorter wavelengths compared to more metal-rich systems, a sign of a clumpier medium in dwarf galaxies. The PAH mass fraction and dust temperature distribution are found to be driven mostly by the specific star formation rate, sSFR, with secondary effects from metallicity. The correlations between metallicity and dust mass or total-IR luminosity are direct consequences of the stellar mass-metallicity relation. The dust-to-stellar mass ratios of metal-rich sources follow the well-studied trend of decreasing ratio for decreasing sSFR. The relation is more complex for low-metallicity galaxies with high sSFR, and depends on the chemical evolutionary stage of the source (i.e. gas-to-dust mass ratio). Dust growth processes in the ISM play a key role in the dust mass build-up with respect to the stellar content at high sSFR and low metallicity. We conclude that the evolution of the dust properties from metal-poor to metal-rich galaxies derives from a complex interplay between star formation activity, stellar mass, and metallicity.
- 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/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/A+AS/117/227
- Title:
- Dwarf effective temperatures
- Short Name:
- J/A+AS/117/227
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have applied the InfraRed Flux Method (IRFM) to a sample of 475 dwarfs and subdwarfs in order to derive their effective temperatures with a mean accuracy of about 1.5%. We have used the new homogeneous grid of theoretical model atmosphere flux distributions developed by Kurucz (1991, 1993) for the application of the IRFM. The atmospheric parameters of the stars cover, roughly, the ranges: 3500K<=T_eff_<=8000K; -3.5<=[Fe/H]<=+0.5; 3.5<=log(g)<=5. The monochromatic infrared fluxes at the continuum, and the bolometric fluxes are derived using recent results, which satisfy the accuracy requirements of the work.
- 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/A+AS/107/365
- Title:
- Dwarfs and subdwarfs IR photometry
- Short Name:
- J/A+AS/107/365
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results of a long term programme of broad band JHK photometry, for a sample of 360 late type stars, made at the Observatorio del Teide (Tenerife, Spain) are presented.
- ID:
- ivo://CDS.VizieR/J/ApJ/693/1484
- Title:
- Early optical afterglow catalog
- Short Name:
- J/ApJ/693/1484
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present multicolor optical observations of long-duration {gamma}-ray bursts (GRBs) made over a three-year period with the robotic Palomar 60 inch telescope (P60). Our sample consists of all 29 events discovered by Swift for which P60 began observations less than 1hr after the burst trigger. We were able to recover 80% of the optical afterglows from this prompt sample, and we attribute this high efficiency to our red coverage. Like Melandri et al. (2008, Cat. J/ApJ/686/1209), we find that a significant fraction (~50%) of Swift events show a suppression of the optical flux with regard to the X-ray emission (the so-called "dark" bursts). Our multicolor photometry demonstrates this is likely due in large part to extinction in the host galaxy. We argue that previous studies, by selecting only the brightest and best-sampled optical afterglows, have significantly underestimated the amount of dust present in typical GRB environments.
- ID:
- ivo://CDS.VizieR/J/ApJ/810/61
- Title:
- Early-type EBs with intermediate orbital periods
- Short Name:
- J/ApJ/810/61
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyze 221 eclipsing binaries (EBs) in the Large Magellanic Cloud with B-type main-sequence (MS) primaries (M_1_~4-14 M_{sun}_) and orbital periods P=20-50 days that were photometrically monitored by the Optical Gravitational Lensing Experiment. We utilize our three-stage automated pipeline to (1) classify all 221 EBs, (2) fit physical models to the light curves of 130 detached well-defined EBs from which unique parameters can be determined, and (3) recover the intrinsic binary statistics by correcting for selection effects. We uncover two statistically significant trends with age. First, younger EBs tend to reside in dustier environments with larger photometric extinctions, an empirical relation that can be implemented when modeling stellar populations. Second, younger EBs generally have large eccentricities. This demonstrates that massive binaries at moderate orbital periods are born with a Maxwellian "thermal" orbital velocity distribution, which indicates they formed via dynamical interactions. In addition, the age-eccentricity anticorrelation provides a direct constraint for tidal evolution in highly eccentric binaries containing hot MS stars with radiative envelopes. The intrinsic fraction of B-type MS stars with stellar companions q=M_2_/M_1_>0.2 and orbital periods P=20-50 days is (7+/-2)%. We find early-type binaries at P=20-50 days are weighted significantly toward small mass ratios q~0.2-0.3, which is different than the results from previous observations of closer binaries with P<20 days. This indicates that early-type binaries at slightly wider orbital separations have experienced substantially less competitive accretion and coevolution during their formation in the circumbinary disk.
