- ID:
- ivo://CDS.VizieR/J/ApJ/806/52
- Title:
- 8 Fermi GRB afterglows follow-up
- Short Name:
- J/ApJ/806/52
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Fermi Gamma-ray Space Telescope has greatly expanded the number and energy window of observations of gamma-ray bursts (GRBs). However, the coarse localizations of tens to a hundred square degrees provided by the Fermi GRB Monitor instrument have posed a formidable obstacle to locating the bursts' host galaxies, measuring their redshifts, and tracking their panchromatic afterglows. We have built a target-of-opportunity (TOO) mode for the intermediate Palomar Transient Factory (iPTF) in order to perform targeted searches for Fermi afterglows. Here, we present the results of one year of this program: 8 afterglow discoveries out of 35 searches. Two of the bursts with detected afterglows (GRBs 130702A and 140606B) were at low redshift (z=0.145 and 0.384, respectively) and had spectroscopically confirmed broad-line Type Ic supernovae. We present our broadband follow-up including spectroscopy as well as X-ray, UV, optical, millimeter, and radio observations. We study possible selection effects in the context of the total Fermi and Swift GRB samples. We identify one new outlier on the Amati relation. We find that two bursts are consistent with a mildly relativistic shock breaking out from the progenitor star rather than the ultra-relativistic internal shock mechanism that powers standard cosmological bursts. Finally, in the context of the Zwicky Transient Facility, we discuss how we will continue to expand this effort to find optical counterparts of binary neutron star mergers that may soon be detected by Advanced LIGO and Virgo.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+AS/131/197
- Title:
- F, G and K stars BVRI photometry
- Short Name:
- J/A+AS/131/197
- Date:
- 15 Dec 2021 08:12:40
- Publisher:
- CDS
- Description:
- We present accurate BV(RI)c photometry for a sample of F, G and K stars detected in selected areas of the ROSAT all-sky survey (RASS). We have used the photometry, in addition to low-resolution spectroscopy, to estimate spectral classifications, distances and X-ray luminosities. The log(L_X_/L_V_) in the sample lies below -2. Although the sample contains also nearby, inactive stars, it is dominated by active objects. The median X-ray luminosity in our sample is <L_X_>=29.88 and the mean value of the hardness ratios <HR1>=0.13+/-0.35. We compare the derived X-ray luminosity function with similar functions obtained from the serendipitous samples of the Einstein Observatory medium sensitivity survey (EMSS, Cat. <IX/15>) and EXOSAT (Cat. <J/A+AS/115/41>). Our sample is completely consistent with the EMSS sample of solar type stars, indicating that both our sources and the EMSS sources are representative of the high galactic latitude X-ray stellar population. We do not find extremely active stars (log(L_X_)>=32), as are found in the EMSS sample, and we argue that these objects are rare.
- ID:
- ivo://CDS.VizieR/J/MNRAS/393/1467
- Title:
- Field early-type galaxies at 0.2<z<0.8
- Short Name:
- J/MNRAS/393/1467
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We explore the properties of 24 field early-type galaxies in the redshift range 0.20<z<0.75 down to M_B<=-19.30 in a sample extracted from the FORS Deep Field and the William Herschel Deep Field. Target galaxies were selected on the basis of a combination of luminosity, spectrophotometric type, morphology and photometric redshift or broad-band colours. High signal-to-noise intermediate-resolution spectroscopy has been acquired at the Very Large Telescope, complemented by deep high-resolution imaging with the Advanced Camera for Surveys onboard the HST and additional ground-based multi-band photometry. All galaxy spectra were observed under sub-arcsecond conditions and allow to derive accurate kinematics and stellar population properties of the galaxies. To clarify the low level of star formation detected in some galaxies, we identify the amount of active galactic nuclei (AGN) activity in our sample using archive data of Chandra and XMM-Newton X-ray surveys. None of the galaxies in our sample were identified as secure AGN sources based on their X-ray emission. The rest-frame B and K-band scaling relations of the Faber-Jackson relation and the Fundamental Plane display a moderate evolution for the field early-type galaxies. Lenticular (S0) galaxies feature on average a stronger luminosity evolution and bluer rest-frame colours which can be explained that they comprise more diverse stellar populations compared to elliptical galaxies. The evolution of the FP can be interpreted as an average change in the dynamical (effective) mass-to-light ratio of our galaxies as <{Delta}log(M/L_B_)/z>=-0.74+/-0.08. The M/L evolution of these field galaxies suggests a continuous mass assembly of field early-type galaxies during the last 5Gyr, that gets support by recent studies of field galaxies up to z~1. Independent evidence for recent star formation activity is provided by spectroscopic (OII emission, Hdelta) and photometric (rest-frame broad-band colors) diagnostics. Based on the Hdelta absorption feature we detect a weak residual star formation for galaxies that accounts for 5%-10% in the total stellar mass of these galaxies. The co-evolution in the luminosity and mass of our galaxies favours a downsizing formation process. We find some evidence that our galaxies experienced a period of star formation quenching, possible triggered by AGN activity that is in good agreement with recent results on both observational and theoretical side.
- ID:
- ivo://CDS.VizieR/J/MNRAS/432/2182
- Title:
- FIR bright sources of M83
- Short Name:
- J/MNRAS/432/2182
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate star formation and dust heating in the compact far-infrared (FIR) bright sources detected in the Herschel maps of M83. We use the source extraction code GETSOURCES to detect and extract sources in the FIR, as well as their photometry in the mid-infrared and H{alpha}. By performing infrared spectral energy distribution fitting and applying an H{alpha}-based star formation rate (SFR) calibration, we derive the dust masses and temperatures, SFRs, gas masses and star formation efficiencies (SFEs). The detected sources lie exclusively on the spiral arms and represent giant molecular associations, with gas masses and sizes of 106-108M{sun} and 200-300pc, respectively. The inferred parameters show little to no radial dependence and there is only a weak correlation between the SFRs and gas masses, which suggests that more massive clouds are less efficient at forming stars. Dust heating is mainly due to local star formation. However, although the sources are not optically thick, the total intrinsic young stellar population luminosity can almost completely account for the dust luminosity. This suggests that other radiation sources also contribute to the dust heating and approximately compensate for the unabsorbed fraction of UV light.
- ID:
- ivo://CDS.VizieR/J/ApJ/840/21
- Title:
- FIR data of IR-bright dust-obscured galaxies (DOGs)
- Short Name:
- J/ApJ/840/21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the star-forming activity of a sample of infrared (IR)-bright dust-obscured galaxies (DOGs) that show an extreme red color in the optical and IR regime, (i-[22])_AB_>7.0. Combining an IR-bright DOG sample with the flux at 22{mu}m>3.8mJy discovered by Toba & Nagao (2016ApJ...820...46T) with the IRAS faint source catalog version 2 and AKARI far-IR (FIR) all-sky survey bright source catalog version 2, we selected 109 DOGs with FIR data. For a subsample of seven IR-bright DOGs with spectroscopic redshifts (0.07<z<1.0) that were obtained from the literature, we estimated their IR luminosity, star formation rate (SFR), and stellar mass based on the spectral energy distribution fitting. We found that (1) the WISE 22{mu}m luminosity at the observed frame is a good indicator of IR luminosity for IR-bright DOGs and (2) the contribution of the active galactic nucleus to IR luminosity increases with IR luminosity. By comparing the stellar mass and SFR relation for our DOG sample and the literature, we found that most of the IR-bright DOGs lie significantly above the main sequence of star-forming galaxies at similar redshift, indicating that the majority of IRAS- or AKARI-detected IR-bright DOGs are starburst galaxies.
- ID:
- ivo://CDS.VizieR/J/ApJ/849/63
- Title:
- FIR-mm data of YSOs in star-forming regions
- Short Name:
- J/ApJ/849/63
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Far-infrared and (sub)millimeter fluxes can be used to study dust in protoplanetary disks, the building blocks of planets. Here, we combine observations from the Herschel Space Observatory with ancillary data of 284 protoplanetary disks in the Taurus, Chamaeleon I, and Ophiuchus star-forming regions, covering from the optical to mm/cm wavelengths. We analyze their spectral indices as a function of wavelength and determine their (sub)millimeter slopes when possible. Most disks display observational evidence of grain growth, in agreement with previous studies. No correlation is found between other tracers of disk evolution and the millimeter spectral indices. A simple disk model is used to fit these sources, and we derive posterior distributions for the optical depth at 1.3mm and 10au, the disk temperature at this same radius, and the dust opacity spectral index {beta}. We find the fluxes at 70{mu}m to correlate strongly with disk temperatures at 10au, as derived from these simple models. We find tentative evidence for spectral indices in Chamaeleon I being steeper than those of disks in Taurus/Ophiuchus, although more millimeter observations are needed to confirm this trend and identify its possible origin. Additionally, we determine the median spectral energy distribution of each region and find them to be similar across the entire wavelength range studied, possibly due to the large scatter in disk properties and morphologies.
- ID:
- ivo://CDS.VizieR/J/A+A/575/A80
- Title:
- FIR photometry of 3CR galaxies
- Short Name:
- J/A+A/575/A80
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Herschel (PACS and SPIRE) far-infrared (FIR) photometry of a complete sample of z>1 3CR sources, from the Herschel guaranteed time project The Herschel Legacy of distant radio-loud AGN. Combining these with existing Spitzer photometric data, we perform an infrared (IR) spectral energy distribution (SED) analysis of these landmark objects in extragalactic research to study the star formation in the hosts of some of the brightest active galactic nuclei (AGN) known at any epoch. Accounting for the contribution from an AGN-powered warm dust component to the IR SED, about 40% of our objects undergo episodes of prodigious, ULIRG-strength star formation, with rates of hundreds of solar masses per year, coeval with the growth of the central supermassive black hole. Median SEDs imply that the quasar and radio galaxy hosts have similar FIR properties, in agreement with the orientation-based unification for radio-loud AGN. The star-forming properties of the AGN hosts are similar to those of the general population of equally massive non-AGN galaxies at comparable redshifts, thus there is no strong evidence of universal quenching of star formation (negative feedback) within this sample. Massive galaxies at high redshift may be forming stars prodigiously, regardless of whether their supermassive black holes are accreting or not.
- ID:
- ivo://CDS.VizieR/J/ApJ/768/13
- Title:
- FIR properties of SDSS type 1 quasars
- Short Name:
- J/ApJ/768/13
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use the Spitzer Space Telescope Enhanced Imaging Products and the Spitzer Archival Far-InfraRed Extragalactic Survey to study the spectral energy distributions (SEDs) of spectroscopically confirmed type 1 quasars selected from the Sloan Digital Sky Survey (SDSS). By combining the Spitzer and SDSS data with the Two Micron All Sky Survey, we are able to construct a statistically robust rest-frame 0.1-100{mu}m type 1 quasar template. We find that the quasar population is well-described by a single power-law SED at wavelengths less than 20{mu}m, in good agreement with previous work. However, at longer wavelengths, we find a significant excess in infrared luminosity above an extrapolated power-law, along with significant object-to-object dispersion in the SED. The mean excess reaches a maximum of 0.8dex at rest-frame wavelengths near 100{mu}m.
- ID:
- ivo://CDS.VizieR/J/ApJ/811/58
- Title:
- FIR properties of SDSS 0.1<z<5 quasars
- Short Name:
- J/ApJ/811/58
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the public data from the Herschel wide-field surveys, we study the far-infrared properties of optical-selected quasars from the Sloan Digital Sky Survey. Within the common area of ~172deg^2^, we have identified the far-infrared counterparts for 354 quasars, among which 134 are highly secure detections in the Herschel 250um band (signal-to-noise ratios >=5). This sample is the largest far-infrared quasar sample of its kind, and spans a wide redshift range of 0.14<=z<=4.7. Their far-infrared spectral energy distributions, which are due to the cold-dust components within the host galaxies, are consistent with being heated by active star formation. In most cases (>~80%), their total infrared luminosities as inferred from only their far-infrared emissions (L_IR_^(cd)^) already exceed 10^12^L_{sun}_, and thus these objects qualify as ultra-luminous infrared galaxies. There is no correlation between L_IR_^(cd)^ and the absolute magnitudes, the black hole masses or the X-ray luminosities of the quasars, which further support that their far-infrared emissions are not due to their active galactic nuclei. A large fraction of these objects (>~50%-60%) have star-formation rates >~300M_{sun}_/yr. Such extreme starbursts among optical quasars, however, is only a few percent. This fraction varies with redshift, and peaks at around z~2. Among the entire sample, 136 objects have secure estimates of their cold-dust temperatures (T), and we find that there is a dramatic increasing trend of T with increasing L_IR_^(cd)^. We interpret this trend as the envelope of the general distribution of infrared galaxies on the (T, L_IR_^(cd)^) plane.
- ID:
- ivo://CDS.VizieR/J/ApJS/197/19
- Title:
- First brown dwarfs discovered by WISE
- Short Name:
- J/ApJS/197/19
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present ground-based spectroscopic verification of 6 Y dwarfs (see also Cushing et al., 2011ApJ...743...50C), 89 T dwarfs, 8 L dwarfs, and 1 M dwarf identified by the Wide-field Infrared Survey Explorer (WISE). Eighty of these are cold brown dwarfs with spectral types >=T6, six of which have been announced earlier by Mainzer et al. (2011ApJ...726...30M) and Burgasser et al. (2011ApJ...735..116B). We present color-color and color-type diagrams showing the locus of M, L, T, and Y dwarfs in WISE color space. Near-infrared and, in a few cases, optical spectra are presented for these discoveries. Near-infrared classifications as late as early Y are presented and objects with peculiar spectra are discussed. Using these new discoveries, we are also able to extend the optical T dwarf classification scheme from T8 to T9. After deriving an absolute WISE 4.6um (W2) magnitude versus spectral type relation, we estimate spectrophotometric distances to our discoveries. We also use available astrometric measurements to provide preliminary trigonometric parallaxes to four of our discoveries, which have types of L9 pec (red), T8, T9, and Y0; all of these lie within 10pc of the Sun. The Y0 dwarf, WISE 1541-2250, is the closest at 2.8^+1.3^_-0.6_pc; if this 2.8pc value persists after continued monitoring, WISE 1541-2250 will become the seventh closest stellar system to the Sun. Another 10 objects, with types between T6 and >Y0, have spectrophotometric distance estimates also placing them within 10pc. The closest of these, the T6 dwarf WISE 1506+7027, is believed to fall at a distance of ~4.9pc. WISE multi-epoch positions supplemented with positional info primarily from the Spitzer/Infrared Array Camera allow us to calculate proper motions and tangential velocities for roughly one-half of the new discoveries.
