- ID:
- ivo://CDS.VizieR/J/A+A/526/A151
- Title:
- Hi-Gal sources distance determination
- Short Name:
- J/A+A/526/A151
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Hi-GAL, an open time key-project of the Herschel satellite, was awarded 343 hours observing time to carry out a 5-band photometric imaging survey at 70, 160, 250, 350, and 500um of a |b|<=1{deg} wide strip of the Milky Way Galactic plane in the longitude range -70{deg}<=l<=70{deg}. Two 2{deg}x2{deg} fields centred at l=30{deg} and l=59{deg} have been observed with the SPIRE and PACS photometric cameras in parallel mode during the Herschel science demonstration phase (SDP). From the images, compact sources are extracted for which the distance must be established in order to determine their physical properties. The aim of this paper is to present the distance determination strategy for the Hi-GAL compact sources. We illustrate this strategy for the two fields at l=30{deg} and l=59{deg}.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/817/2
- Title:
- High angular resolution spectroscopy of NGC 1277
- Short Name:
- J/ApJ/817/2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The nearby lenticular galaxy NGC 1277 is thought to host one of the largest black holes known, however the black hole mass measurement is based on low spatial resolution spectroscopy. In this paper, we present Gemini Near-infrared Integral Field Spectrometer observations assisted by adaptive optics. We map out the galaxy's stellar kinematics within ~440pc of the nucleus with an angular resolution that allows us to probe well within the region where the potential from the black hole dominates. We find that the stellar velocity dispersion rises dramatically, reaching ~550km/s at the center. Through orbit-based, stellar-dynamical models we obtain a black hole mass of (4.9+/-1.6)x10^9^M_{sun}_ (1{sigma} uncertainties). Although the black hole mass measurement is smaller by a factor of ~3 compared to previous claims based on large-scale kinematics, NGC 1277 does indeed contain one of the most massive black holes detected to date, and the black hole mass is an order of magnitude larger than expectations from the empirical relation between black hole mass and galaxy luminosity. Given the galaxy's similarities to the higher redshift (z~2) massive quiescent galaxies, NGC 1277 could be a relic, passively evolving since that period. A population of local analogs to the higher redshift quiescent galaxies that also contain over-massive black holes may suggest that black hole growth precedes that of the host galaxy.
- ID:
- ivo://CDS.VizieR/J/PASJ/57/13
- Title:
- High-dispersion spectra of nearby F-K stars
- Short Name:
- J/PASJ/57/13
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Towards constructing a system of high-dispersion spectroscopic standard stars with well-established abundances, so that adequate reference stars of similar properties may be found for precise differential abundance studies of any near-solar type stars, we have collected high-resolution (R~70000) echelle spectra for 160 F-K dwarfs and subgiants of the solar neighborhood in three wavelength regions (5000-6200{AA}, 5800-7000{AA}, and 7600-8800{AA}) at Okayama Astrophysical Observatory. This spectra database is open to the public.
- ID:
- ivo://CDS.VizieR/J/ApJ/705/509
- Title:
- High-dispersion spectrum of the PN DdDm 1
- Short Name:
- J/ApJ/705/509
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the High Dispersion Spectrograph (HDS) at the Subaru Telescope, we secured the high-resolution line spectra in the 3600-7500{AA} wavelength range of the Galactic halo planetary nebula DdDm 1. We also analyzed the Hubble Space Telescope Faint Object Spectrograph data in the 1200-6730{AA} wavelength range. The diagnostic results indicate the electron temperatures of T_{epsilon}_~11000-14000K and the electron number densities of N_{epsilon}_~2000-10500cm^-3^. In spite of high gaseous temperatures, we have not detected high excitation lines, e.g., HeII. We derived abundance based on the ionic concentration of permitted and forbidden lines and the photoionization model. A comparison of the ionic concentrations from forbidden lines to recombination lines shows the abundance discrepancy between them. We tested various possibilities, e.g., temperature fluctuation and high-density blob components, to explain the discrepancy. The high-density components or density fluctuation might be partly responsible for the discrepancy. DdDm 1 shows a low carbon abundance that corresponds to metal-poor stars, [Fe/H]<=-1. Assuming a distance of 10kpc to DdDm 1, theoretical models suggest that the central star has T_eff_~39000K and L~2000-3000L_{sun}_. The relatively high gas temperatures appear to be caused by very low heavy elemental abundances or insufficient coolants in the shell gas. Its progenitor, born in an extremely carbon-poor environment as an initial mass of about 0.9M_{sun}_, had probably experienced only the first dredge-up.
- ID:
- ivo://CDS.VizieR/J/A+A/620/A118
- Title:
- Highly Accreting Quasars: SDSS Low z Catalog
- Short Name:
- J/A+A/620/A118
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The most highly accreting quasars are of special interest in studies of the physics of active galactic nuclei (AGNs) and host galaxy evolution. Quasars accreting at high rates (L/LEdd~1) hold promise for use as "standard candles": distance indicators detectable at very high redshift. However, their observational properties are still largely unknown. We seek to identify a significant number of extreme accretors. A large sample can clarify the main properties of quasars radiating near L/LEdd~1 (in this paper they are designated as extreme Population A quasars or simply as extreme accretors) in the H{beta} spectral range for redshift <~0.8. We use selection criteria derived from four-dimensional Eigenvector 1 (4DE1) studies to identify and analyze spectra for a sample of 334 candidate sources identified from the SDSS DR7 database. The source spectra were chosen to show a ratio R_FeII_ between the FeII emission blend at {lambda}4570 and H{beta}, R_FeII_ > 1. Composite spectra were analyzed for systematic trends as a function of FeII strength, line width, and [OIII] strength. We introduced tighter constraints on the signal-to-noise ratio (S/N) and R_FeII_ values that allowed us to isolate sources most likely to be extreme accretors. We provide a database of detailed measurements. Analysis of the data allows us to confirm that H{beta} shows a Lorentzian function with a full width at half maximum (FWHM) of H{beta}<=4000km/s. We find no evidence for a discontinuity at 2000km/s in the 4DE1, which could mean that the sources below this FWHM value do not belong to a different AGN class. Systematic [OIII] blue shifts, as well as a blueshifted component in H{beta} are revealed. We interpret the blueshifts as related to the signature of outflowing gas from the quasar central engine. The FWHM of H{beta} is still affected by the blueshifted emission; however, the effect is non-negligible if the FWHM H{beta} is used as a "virial broadening estimator" (VBE). We emphasize a strong effect of the viewing angle on H{beta} broadening, deriving a correction for those sources that shows major disagreement between virial and concordance cosmology luminosity values. The relatively large scatter between concordance cosmology and virial luminosity estimates can be reduced (by an order of magnitude) if a correction for orientation effects is included in the FWHM H{beta} value; outflow and sample definition yield relatively minor effects.
- ID:
- ivo://CDS.VizieR/J/ApJS/169/458
- Title:
- Highly excited H2 in Comets
- Short Name:
- J/ApJS/169/458
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Rotationally resolved molecular hydrogen transitions originating from excitation of highly excited rovibrational levels of the X^1^{SIGMA}^+^_g_ state have been systematically identified for the first time in the Far Ultraviolet Spectroscopic Explorer (FUSE) observation of comets C/2000 WM1 (LINEAR) and C/2001 A2 (LINEAR). Spectral assignments for the observed lines of H_2_ and other atomic and molecular species are given. All observed H_2_ transitions belong to the Lyman (B^1^{SIGMA}^+^_u_-X^1^{sigma}^+^_g_) and Werner (C^1^{PI}_u_-X^1^{SIGMA}^+^_g_) band systems. Resonant excitation of H_2_ by Ly{beta} and other solar lines is very limited.
- ID:
- ivo://CDS.VizieR/J/A+A/625/A103
- Title:
- 19 highmass SFR Herschel spectra and maps
- Short Name:
- J/A+A/625/A103
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The physical conditions during high-mass star formation are poorly understood. Outflow and infall motions have been detected around massive protostellar objects, but their dependence on mass, luminosity, and age is unclear. In addition, physical conditions and molecular abundances are often estimated using simple assumptions such as spherical shape and chemical homogeneity, which may limit the accuracy of the results. We aim to characterize the dust and gas distribution and kinematics of the envelopes of high-mass protostars. In particular, we search for infall motions, abundance variations, and deviations from spherical symmetry, using Herschel data from the WISH program. We used HIFI maps of the 987GHz H_2_O 2_02_-1_11_ emission to measure the sizes and shapes of 19 high-mass protostellar envelopes. To identify infall, we used HIFI spectra of the optically thin C^18^O 9-8 and H_2_^18^O 1_11_-0_00_ lines. The high-J C^18^O line traces the warm central material and redshifted H_2_^18^O 1_11_-0_00_ absorption indicates material falling onto the warm core. We probe small-scale chemical differentiation by comparing H_2_O 752 and 987GHz spectra with those of H_2_^18^O. Our measured radii of the central part of the H_2_O 2_02_-1_11_ emission are 30-40% larger than the predictions from spherical envelope models, and axis ratios are <2, which we consider good agreement. For 11 of the 19 sources, we find a significant redshift of the H_2_^18^O 1_11_-0_00_ line relative to C^18^O 9-8. The inferred infall velocities are 0.6-3.2km/s, and estimated mass inflow rates range from 7x10^-5^ to 2x10^-2^M_{sun}_/yr. The highest mass inflow rates seem to occur toward the sources with the highest masses, and possibly the youngest ages. The other sources show either expanding motions or H_2_^18^O lines in emission. The H_2_^18^O 1_11_-0_00_ line profiles are remarkably similar to the differences between the H_2_O 2_02_-1_11_ and 2_11_-2_02_ profiles, suggesting that the H_2_^18^O line and the H_2_O 2_02_-1_11_ absorption originate just inside the radius where water evaporates from grains, typically 1000-5000au from the center. In some sources, the H_2_^18^O line is detectable in the outflow, where no C^18^O emission is seen. Together, the H_2_^18^O absorption and C^18^O emission profiles show that the water abundance around high-mass protostars has at least three levels: low in the cool outer envelope, high within the 100K radius, and very high in the outflowing gas. Thus, despite the small regions, the combination of lines presented in this work reveals systematic inflows and chemical information about the outflows.
- ID:
- ivo://CDS.VizieR/J/AJ/159/30
- Title:
- High proper-motion M-type stars spectroscopic obs.
- Short Name:
- J/AJ/159/30
- Date:
- 11 Mar 2022
- Publisher:
- CDS
- Description:
- Large numbers of low-to-medium-resolution spectra of M-type dwarf stars from both the local Galactic disk and halo are available from various surveys. In order to fully exploit these data, we develop a template-fit method using a set of empirically assembled M dwarf/subdwarf classification templates, based on the measurements of the TiO and CaH molecular bands near 7000{AA}, which are used to classify M dwarfs/subdwarfs by spectral type and metallicity class. We further present a pipeline to automatically determine the effective temperature Teff, metallicity [M/H], {alpha}-element to iron abundance ratio [{alpha}/Fe], and surface gravity logg of M dwarfs/subdwarfs using the latest version of BT-Settl model atmospheres. We apply these methods to a set of low-to-medium-resolution spectra of 1544 high proper-motion ({mu}>=0.4"/yr) M dwarfs/subdwarfs, collected at the MDM observatory, Lick Observatory, Kitt-Peak National Observatory, and Cerro-Tololo Interamerican Observatory.
- ID:
- ivo://CDS.VizieR/J/ApJ/725/394
- Title:
- High-redshift Ly{alpha} emitters
- Short Name:
- J/ApJ/725/394
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an atlas of 88 z~5.7 and 30 z~6.5 Ly{alpha} emitters obtained from a wide-field narrowband survey. We combined deep narrowband imaging in 120{AA} bandpass filters centered at 8150{AA} and 9140{AA} with deep BVRIz broadband imaging to select high-redshift galaxy candidates over an area of 4180arcmin^2^. The goal was to obtain a uniform selection of comparable depth over the seven targeted fields in the two filters. For the GOODS-North region of the Hubble Deep Field-North field, we also selected candidates using a 120{AA} filter centered at 9210{AA}. We made spectroscopic observations with Keck DEIMOS of nearly all the candidates to obtain the final sample of Ly{alpha} emitters. At the 3.3{AA} resolution of the DEIMOS observations the asymmetric profile for Ly{alpha} emission can be clearly seen in the spectra of nearly all the galaxies. We show that the spectral profiles are surprisingly similar for many of the galaxies and that the composite spectral profiles are nearly identical at z=5.7 and z=6.5.
- ID:
- ivo://CDS.VizieR/J/ApJ/761/112
- Title:
- High-redshift MgII absorption QSOs with FIRE
- Short Name:
- J/ApJ/761/112
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present initial results from the first systematic survey for Mg II quasar absorption lines at z>2.5. Using infrared spectra of 46 high-redshift quasars, we discovered 111 Mg II systems over a path covering 1.9<z<6.3. Five systems have z>5, with a maximum of z=5.33 --the most distant Mg II system now known. The comoving Mg II line density for weaker systems (W_r_<1.0{AA}) is statistically consistent with no evolution from z=0.4 to 5.5, while that for stronger systems increases three-fold until z~3 before declining again toward higher redshifts. The equivalent width distribution, which fits an exponential, reflects this evolution by flattening as z-->3 before steepening again. The rise and fall of the strong absorbers suggests a connection to the star formation rate density, as though they trace galactic outflows or other byproducts of star formation. The weaker systems' lack of evolution does not fit within this interpretation, but may be reproduced by extrapolating low redshift scaling relations between host galaxy luminosity and absorbing halo radius to earlier epochs. For the weak systems, luminosity-scaled models match the evolution better than similar models based on Mg II occupation of evolving cold dark matter halo masses, which greatly underpredict dN/dz at early times unless the absorption efficiency of small halos is significantly larger at early times. Taken together, these observations suggest that the general structure of Mg II-bearing halos was put into place early in the process of galaxy assembly. Except for a transient appearance of stronger systems near the peak epoch of cosmic star formation, the basic properties of Mg II absorbers have evolved fairly little even as the (presumably) associated galaxy population grew substantially in stellar mass and half-light radius.
