- ID:
- ivo://CDS.VizieR/J/AJ/156/224
- Title:
- Gemini/HST GCP: galaxies in 4 massive clusters
- Short Name:
- J/AJ/156/224
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In order to study stellar populations and galaxy structures at intermediate and high redshift (z=0.2-2.0) and link these properties to those of low-redshift galaxies, there is a need for well-defined local reference samples. Especially for galaxies in massive clusters, such samples are often limited to the Coma cluster galaxies. We present consistently calibrated velocity dispersions and absorption-line indices for galaxies in the central 2 R_500_x2 R_500_ of four massive clusters at z<0.1: Abell 426/Perseus, Abell 1656/Coma, Abell 2029, and Abell 2142. The measurements are based on data from the Gemini Observatory, McDonald Observatory, and Sloan Digital Sky Survey. For bulge-dominated galaxies, the samples are 95% complete in Perseus and Coma and 74% complete in A2029 and A2142, to a limit of M_B,abs_=<-18.5 mag. The data serve as the local reference for our studies of galaxy populations in the higher-redshift clusters that are part of the Gemini/HST Galaxy Cluster Project (GCP). We establish the scaling relations between line indices and velocity dispersions as a reference for the GCP. We derive stellar population parameters, ages, metallicities [M/H], and abundance ratios from line indices, both averaged in bins of velocity dispersion and from individual measurements for galaxies in Perseus and Coma. The zero points of relations between the stellar population parameters and the velocity dispersions limit the allowed cluster-to-cluster variation of the four clusters to +/-0.08 dex in age, +/-0.06 dex in [M/H], +/-0.07 dex in [CN/Fe], and +/-0.03 dex in [Mg/Fe].
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/858/102
- Title:
- Gemini/NIFS and HST obs. of the galaxy M59-UCD3
- Short Name:
- J/ApJ/858/102
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We examine the internal properties of the most massive ultracompact dwarf galaxy (UCD), M59-UCD3, by combining adaptive-optics-assisted near-IR integral field spectroscopy from Gemini/NIFS and Hubble Space Telescope (HST) imaging. We use the multiband HST imaging to create a mass model that suggests and accounts for the presence of multiple stellar populations and structural components. We combine these mass models with kinematics measurements from Gemini/NIFS to find a best-fit stellar mass-to-light ratio (M/L) and black hole (BH) mass using Jeans anisotropic models (JAMs), axisymmetric Schwarzschild models, and triaxial Schwarzschild models. The best-fit parameters in the JAM and axisymmetric Schwarzschild models have BHs between 2.5 and 5.9 million solar masses. The triaxial Schwarzschild models point toward a similar BH mass but show a minimum {chi}^2^ at a BH mass of ~0. Models with a BH in all three techniques provide better fits to the central V_rms_ profiles, and thus we estimate the BH mass to be 4.2_-1.7_^+2.1^x10^6^M_{sun}_ (estimated 1{sigma} uncertainties). We also present deep radio imaging of M59-UCD3 and two other UCDs in Virgo with dynamical BH mass measurements, and we compare these to X-ray measurements to check for consistency with the fundamental plane of BH accretion. We detect faint radio emission in M59cO but find only upper limits for M60-UCD1 and M59-UCD3 despite X-ray detections in both these sources. The BH mass and nuclear light profile of M59-UCD3 suggest that it is the tidally stripped remnant of a ~10^9^-10^10^M_{sun}_ galaxy.
- ID:
- ivo://CDS.VizieR/J/AJ/155/226
- Title:
- Gemini Planet Imager spectra of HR 8799 c/d/e
- Short Name:
- J/AJ/155/226
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We explore Karhunen Loeve Image Projection (KLIP) forward modeling spectral extraction on Gemini Planet Imager coronagraphic data of HR 8799, using PyKLIP, and show algorithm stability with varying KLIP parameters. We report new and re-reduced spectrophotometry of HR 8799 c, d, and e in the H and K bands. We discuss a strategy for choosing optimal KLIP PSF subtraction parameters by injecting simulated sources and recovering them over a range of parameters. The K1/K2 spectra for HR 8799 c and d are similar to previously published results from the same data set. We also present a K-band spectrum of HR 8799 e for the first time and show that our H-band spectra agree well with previously published spectra from the VLT/SPHERE instrument. We show that HR 8799 c and d show significant differences in their H and K spectra, but do not find any conclusive differences between d and e, nor between c and e, likely due to large error bars in the recovered spectrum of e. Compared to M-, L-, and T-type field brown dwarfs, all three planets are most consistent with mid- and late-L spectral types. All objects are consistent with low gravity, but a lack of standard spectra for low gravity limit the ability to fit the best spectral type. We discuss how dedicated modeling efforts can better fit HR 8799 planets' near-IR flux, as well as how differences between the properties of these planets can be further explored.
- ID:
- ivo://CDS.VizieR/J/ApJ/901/123
- Title:
- Ghostly damped Ly{alpha} systems in SDSS DR14
- Short Name:
- J/ApJ/901/123
- Date:
- 18 Feb 2022 09:18:37
- Publisher:
- CDS
- Description:
- We report the discovery of 59 new ghostly absorbers from the Sloan Digital Sky Survey Data Release 14. These absorbers, with z_abs_~z_QSO_, reveal no Ly{alpha} absorption, and they are mainly identified through the detection of strong metal absorption lines in the spectra. The number of such previously known systems is 30. The new systems are found with the aid of machine-learning algorithms. The spectra of 41 (out of total of 89) absorbers also cover the Ly{beta} spectral region. By fitting the damping wings of the Ly{beta} absorption in the stacked spectrum of 21 (out of 41) absorbers with relatively stronger Ly{beta} absorption, we measured an HI column density of log N(HI)=21.50. This column density is 0.5dex higher than that of the previous work. We also found that the metal absorption lines in the stacked spectrum of the 21 ghostly absorbers with stronger Ly{beta} absorption have similar properties as those in the stacked spectrum of the remaining systems. This circumstantial evidence strongly suggests that the majority of our ghostly absorbers are indeed DLAs.
- ID:
- ivo://CDS.VizieR/J/ApJ/888/85
- Title:
- Ghostly strong Lya absorbers in SDSS DR12
- Short Name:
- J/ApJ/888/85
- Date:
- 25 Oct 2021 10:15:53
- Publisher:
- CDS
- Description:
- We have searched the Sloan Digital Sky Survey Data Release 12 for ghostly strong Ly{alpha} (DLA) systems. These systems, located at the redshift of the quasars, show strong absorption from low-ionization atomic species but reveal no HI Ly{alpha} absorption. Our search has, for the first time, resulted in a sample of 30 homogeneously selected ghostly absorbers with z_QSO_>2.0. Thirteen of the ghostly absorbers exhibit absorption from other HI Lyman series lines. The lack of Ly{alpha} absorption in these absorbers is consistent with them being dense and compact with projected sizes smaller than the broad-line region of the background quasar. Although uncertain, the estimated median HI column density of these absorbers is logN(HI)~21.0. We compare the properties of ghostly absorbers with those of eclipsing DLAs that are high-column-density absorbers, located within 1500km/s of the quasar emission redshift and showing strong Ly{alpha} emission in their DLA trough. We discover an apparent sequence in the observed properties of these DLAs, with ghostly absorbers showing wider HI kinematics, stronger absorptions from high-ionization species, CII and SiII excited states, and a higher level of dust extinction. Since we estimate that all these absorbers have similar metallicities, logZ/Z_{sun}_~-1.0, we conclude that ghostly absorbers are part of the same population as eclipsing DLAs, except that they are denser and located closer to the central active galactic nuclei.
- ID:
- ivo://CDS.VizieR/J/A+A/413/233
- Title:
- 12.2 GHz methanol survey
- Short Name:
- J/A+A/413/233
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results of 12.2GHz methanol maser survey done with the Torun 32 meter radio telescope. We examined 261 star forming sites, known as containing 6.7GHz maser emission sources. The survey resulted in 49 sources with maser line detection, with 21 previously unknown emissions. All detected 12.2GHz masers have been observed at 6.7GHz transition. Only one 12.2GHz source has no 6.7GHz counterpart. We compared basic spectral line properties at both transitions. In a few cases we observed absorption features and emitting counterparts in the other monitored frequency, at the same velocity.
- ID:
- ivo://CDS.VizieR/J/A+A/658/A39
- Title:
- 31.0-50.3 GHz observations of IRC+10216
- Short Name:
- J/A+A/658/A39
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- The carbon-rich envelope of the asymptotic giant branch star CW Leo, IRC+10216, is one of the richest molecular sources in the sky. Available spectral surveys below 51GHz are more than 25 years old, and new work is needed. Characterizing the rich molecular content of this source, specially for heavy species, requires carrying out very sensitive spectral surveys at low frequencies. In particular, we have achieved an rms in the range 0.2-0.6mK per MHz. Long Q band (31.0-50.3GHz) single-dish integrations were carried out with the Yebes-40m telescope using specifically built receivers. The most recent line catalogs were used to identify the lines. The data contain 652 spectral features, corresponding to 713 transitions from 81 species (we count the isomers, isotopologs, and ortho/para species separately). Only 57 unidentified lines remain with signal-to-noise ratios >=3. Some new species and/or vibrational modes have been discovered for the first time with this survey. This IRC+10216 spectral survey is by far the most sensitive survey carried out to date in the Q band. It therefore provides the most complete view of IRC+10216 from 31.0 to 50.3GHz, giving unique information about its molecular content, especially for heavy species. Rotational diagrams built from the data provide valuable information about the physical conditions and chemical content of this circumstellar envelope.
- ID:
- ivo://CDS.VizieR/J/A+A/393/115
- Title:
- 86GHz SiO maser survey of late-type stars
- Short Name:
- J/A+A/393/115
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 86GHz (v=1, J=2-1) SiO maser line observations with the IRAM 30-m telescope of a sample of 444 late-type stars in the Inner Galaxy (-4{deg}<l<+30{deg}). These stars were selected on basis of their infrared magnitudes and colours from the ISOGAL and MSX catalogues. SiO maser emission was detected in 271 sources, and their line-of-sight velocities indicate that the stars are located in the Inner Galaxy. These new detections double the number of line-of-sight velocities available from previous SiO and OH maser observations in the area covered by our survey and are, together with other samples of e.g. OH/IR stars, useful for kinematic studies of the central parts of the Galaxy.
- ID:
- ivo://CDS.VizieR/J/A+A/625/A147
- Title:
- 80-116GHz spectrum of L483
- Short Name:
- J/A+A/625/A147
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An exhaustive chemical characterization of dense cores is mandatory to our understanding of chemical composition changes from a starless to a protostellar stage. However, only a few sources have had their molecular composition characterized in detail. Here we present a 3mm line survey of L483, a dense core around a Class 0 protostar, which was observed with the IRAM 30m telescope in the 80-116GHz frequency range. We detected 71 molecules (140 including different isotopologs), most of which are present in the cold and quiescent ambient cloud according to their narrow lines (FWHM~0.5km/s) and low rotational temperatures (<~10K). Of particular interest among the detected molecules are the cis isomer of HCOOH, the complex organic molecules HCOOCH_3_, CH_3_OCH_3_, and C_2_H_5_OH, a wide variety of carbon chains, nitrogen oxides like N_2_O, and saturated molecules like CH_3_SH, in addition to eight new interstellar molecules (HCCO, HCS, HSC, NCCNH^+^, CNCN, NCO, H_2_NCO^+^, and NS^+^) whose detection has already been reported. In general, fractional molecular abundances in L483 are systematically lower than in TMC-1 (especially for carbon chains), tend to be higher than in L1544 and B1-b, and are similar to those in L1527. Apart from the overabundance of carbon chains in TMC-1, we find that L483 does not have a marked chemical differentiation with respect to starless/prestellar cores like TMC-1 and L1544, although it does chemically differentiate from Class 0 hot corino sources like IRAS 16293-2422. This fact suggests that the chemical composition of the ambient cloud of some Class 0 sources could be largely inherited from the dark cloud starless/prestellar phase. We explore the use of potential chemical evolutionary indicators, such as the HNCO/C_3_S, SO_2_/C_2_S, and CH_3_SH/C_2_S ratios, to trace the prestellar/protostellar transition. We also derived isotopic ratios for a variety of molecules, many of which show isotopic ratios close to the values for the local interstellar medium (remarkably all those involving ^34^S and ^33^S), while there are also several isotopic anomalies like an extreme depletion in ^13^C for one of the two isotopologs of c-C_3_H_2_, a drastic enrichment in ^18^O for SO and HNCO (SO being also largely enriched in ^17^O), and different abundances for the two ^13^C substituted species of C_2_H and the two ^15^N substituted species of N_2_H^+^. We report the first detection in space of some minor isotopologs and quantify for the first time the deuterium fractionation for HDCCO and c-C_3_D. The exhaustive chemical characterization of L483 presented here, together with similar studies of other prestellar and protostellar sources, should allow us to identify the main factors that regulate the chemical composition of cores along the process of formation of low-mass protostars.
- ID:
- ivo://CDS.VizieR/J/MNRAS/445/1745
- Title:
- Giant Gemini GMOS survey. I.
- Short Name:
- J/MNRAS/445/1745
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present spectra of 163 quasars at z_em_>4.4 taken with the Gemini Multi Object Spectrometers, the largest publicly available sample of high-quality (signal-to-noise ratio S/N~20 per 1.85{AA} pixel) low-resolution (full width at half maximum FWHM~320km/s) rest-frame ultraviolet quasar spectra at these redshifts. The sample was selected from SDSS Data Release 7 with the aim to obtain high-S/N follow-up spectra of the intergalactic HI Lyman series and Lyman continuum absorption at high redshift. Each quasar was observed with the GMOS B600 (FWHM~320km/s) and R400 (FWHM~360km/s) gratings to cover the rest-frame wavelength range from ~850 to ~1500{AA}. Here we make the spectra available in reduced form. The accompanying paper presents a detailed description the sample and a measurement of the mean free path to Lyman limit photons in the IGM, based on stacked rest-frame quasar spectra.
