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Start Over Subject infrared astronomy Content Level Research
91. Binary central star of V510 Pup
ID:
ivo://CDS.VizieR/J/MNRAS/508/2226
Title:
Binary central star of V510 Pup
Short Name:
J/MNRAS/508/2226
Date:
19 Jan 2022 13:43:04
Publisher:
CDS
Description:
Current models predict that binary interactions are a major ingredient in the formation of bipolar planetary nebulae (PNe) and pre-planetary nebulae (PPNe). Despite years of radial velocity (RV) monitoring, the paucity of known binaries amongst the latter systems means data are insufficient to examine this relationship in detail. In this work, we report on the discovery of a long-period (P=2654+/-124d) binary at the centre of the Galactic bipolar PPN IRAS 08005-2356 (V510 Pup), determined from long-term spectroscopic and near-infrared time-series data. The spectroscopic orbit is fitted with an eccentricity of 0.36+/-0.05, which is similar to that of other long-period post-AGB binaries. Time-resolved H{alpha} profiles reveal high-velocity outflows (jets) with deprojected velocities up to 231^+31^_-27_km/s seen at phases when the luminous primary is behind the jet. The outflow traced by H{alpha} is likely produced via accretion on to a main-sequence companion, for which we calculate a mass of 0.63+/-0.13M_{sun}_. This discovery is one of the first cases of a confirmed binary PPN and demonstrates the importance of high-resolution spectroscopic monitoring surveys using large telescopes in revealing binarity among these systems.
92. Binary stars in the Orion Nebula Cluster
ID:
ivo://CDS.VizieR/J/A+A/458/461
Title:
Binary stars in the Orion Nebula Cluster
Short Name:
J/A+A/458/461
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report on a high-spatial-resolution survey for binary stars in the periphery of the Orion Nebula Cluster, at 5-15arcmin (0.65-2pc) from the cluster center. We observed 228 stars with adaptive optics systems, in order to find companions at separations of 0.13"-1.12" (60-500AU), and detected 13 new binaries. Combined with the results of Petr (1998, Ph.D. Thesis, University of Heidelberg), we have a sample of 275 objects, about half of which have masses from the literature and high probabilities to be cluster members.
93. Black hole masses of z~1.4 AGNs from SXDS
ID:
ivo://CDS.VizieR/J/ApJ/761/143
Title:
Black hole masses of z~1.4 AGNs from SXDS
Short Name:
J/ApJ/761/143
Date:
21 Oct 2021
Publisher:
CDS
Description:
In order to investigate the growth of supermassive black holes (SMBHs), we construct the black hole mass function (BHMF) and Eddington ratio distribution function (ERDF) of X-ray-selected broad-line active galactic nuclei (AGNs) at z~1.4 in the Subaru XMM-Newton Deep Survey (SXDS) field. A significant part of the accretion growth of SMBHs is thought to take place in this redshift range. Black hole masses of X-ray-selected broad-line AGNs are estimated using the width of the broad MgII line and 3000{AA} monochromatic luminosity. We supplement the MgII FWHM values with the H{alpha} FWHM obtained from our NIR spectroscopic survey. Using the black hole masses of broad-line AGNs at redshifts between 1.18 and 1.68, the binned broad-line AGN BHMFs and ERDFs are calculated using the V_max_ method. To properly account for selection effects that impact the binned estimates, we derive the corrected broad-line AGN BHMFs and ERDFs by applying the maximum likelihood method, assuming that the ERDF is constant regardless of the black hole mass. We do not correct for the non-negligible uncertainties in virial BH mass estimates. If we compare the corrected broad-line AGN BHMF with that in the local universe, then the corrected BHMF at z=1.4 has a higher number density above 10^8^M_{sun}_ but a lower number density below that mass range. The evolution may be indicative of a downsizing trend of accretion activity among the SMBH population. The evolution of broad-line AGN ERDFs from z=1.4 to 0 indicates that the fraction of broad-line AGNs with accretion rates close to the Eddington limit is higher at higher redshifts.
94. BLAGNs and NLS1s characteristics.
ID:
ivo://CDS.VizieR/J/MNRAS/478/4068
Title:
BLAGNs and NLS1s characteristics.
Short Name:
J/MNRAS/478/4068
Date:
10 Dec 2021 00:54:07
Publisher:
CDS
Description:
investigated narrow-line Seyfert 1 galaxies (NLS1s) at optical, mid-infrared (MIR), and X-ray wavelengths, comparing them to the broad-line active galactic nuclei (BLAGNs). We found that black hole mass, coronal line luminosities, X-ray hardness ratio and X-ray, and optical and MIR luminosities are higher for the BLAGNs than for NLS1s, while policyclic aromatic hydrocarbon (PAH) contribution and the accretion rates are higher for NLS1s. Furthermore, we found some trends among spectral parameters that NLS1s have and BLAGNs do not have. The evolution of FWHM(H{beta}) with the luminosities of MIR and coronal lines, continuum luminosities, PAH contribution, H{beta} broad line luminosity, FWHM[OIII], and EW(H{beta}NLR) are important trends found for NLS1s. That may contribute to the insight that NLS1s are developing AGNs, growing their black holes, while their luminosities and FWHM(H{beta}) consequently grow, and that BLAGNs are mature, larger objects of slower and/or different evolution. Black hole mass is related to PAH contribution only for NLS1s, which may suggest that PAHs are more efficiently destroyed in NLS1s.
95. BLAST 2005: a 10deg^2^ survey in Cygnus X
ID:
ivo://CDS.VizieR/J/ApJ/727/114
Title:
BLAST 2005: a 10deg^2^ survey in Cygnus X
Short Name:
J/ApJ/727/114
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present Cygnus X in a new multi-wavelength perspective based on an unbiased BLAST survey at 250, 350, and 500um, combined with rich data sets for this well-studied region. Our primary goal is to investigate the early stages of high-mass star formation. We have detected 184 compact sources in various stages of evolution across all three BLAST bands. From their well-constrained spectral energy distributions, we obtain the physical properties mass, surface density, bolometric luminosity, and dust temperature. Some of the bright sources reaching 40K contain well-known compact HII regions. We relate these to other sources at earlier stages of evolution via the energetics as deduced from their position in the luminosity-mass (L-M) diagram. The BLAST spectral coverage, near the peak of the spectral energy distribution of the dust, reveals fainter sources too cool (~10K) to be seen by earlier shorter-wavelength surveys like IRAS. We detect thermal emission from infrared dark clouds and investigate the phenomenon of cold "starless cores" more generally. Spitzer images of these cold sources often show stellar nurseries, but these potential sites for massive star formation are "starless" in the sense that to date there is no massive protostar in a vigorous accretion phase.
96. BLAST sources in Galactic plane survey
ID:
ivo://CDS.VizieR/J/ApJ/681/428
Title:
BLAST sources in Galactic plane survey
Short Name:
J/ApJ/681/428
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the first results from a new 250, 350, and 500um Galactic plane survey taken with the Balloon-borne Large-Aperture Submillimeter Telescope (BLAST) in 2005. This survey's primary goal is to identify and characterize high-mass protostellar objects (HMPOs). The region studied here covers 4{deg}^2^ near the open cluster NGC 6823 in the constellation Vulpecula (l=59{deg}). We find 60 compact sources (<60" diameter) detected simultaneously in all three bands. Their SEDs are constrained through BLAST, IRAS, Spitzer MIPS, and MSX photometry, with inferred dust temperatures spanning ~12-40K assuming a dust emissivity index {beta}=1.5. The luminosity-to-mass ratio, a distance-independ ent quantity, spans ~0.2-130L_{sun}_/M_{sun}_. Distances are estimated from coincident ^13^CO(1-0) velocities combined with a variety of other velocity and morphological data in the literature. In total, 49 sources are associated with a molecular cloud complex encompassing NGC 6823 (distance ~2.3kpc), 10 objects with the Perseus arm (~8.5kpc), and one object is probably in the outer Galaxy (~14kpc). Near NGC 6823, the inferred luminosities and masses of BLAST sources span ~40-10^4^L_{sun}_ and ~15-700M_{sun}_, respectively. The mass spectrum is compatible with molecular gas masses in other high-mass star-forming regions. Several luminous sources appear to be ultracompact H II regions powered by early B stars. However, many of the objects are cool, massive gravitationally bound clumps with no obvious internal radiation from a protostar, and hence excellent HMPO candidates.
97. BLAST view of Aquila star-forming region
ID:
ivo://CDS.VizieR/J/ApJ/723/915
Title:
BLAST view of Aquila star-forming region
Short Name:
J/ApJ/723/915
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have carried out the first general submillimeter analysis of the field toward GRSMC 45.46+0.05, a massive star-forming region in Aquila. The deconvolved 6{deg}^2^ (3{deg}x2{deg}) maps provided by BLAST in 2005 at 250, 350, and 500um were used to perform a preliminary characterization of the clump population previously investigated in the infrared, radio, and molecular maps. Interferometric CORNISH data at 4.8GHz have also been used to characterize the Ultracompact HII regions (UCHIIRs) within the main clumps. By means of the BLAST maps, we have produced an initial census of the submillimeter structures that will be observed by Herschel, several of which are known Infrared Dark Clouds.
98. Bright filamentary structures in the ISM
ID:
ivo://CDS.VizieR/J/ApJS/149/365
Title:
Bright filamentary structures in the ISM
Short Name:
J/ApJS/149/365
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a listing of prominent filamentary structures in the interstellar cirrus, selected with an eye toward current and planned far-infrared and submillimeter polarimetry facilities. The filaments were identified on the 100{mu}m plates of the IRAS Sky Survey Atlas (ISSA, Wheelock et al. 1994, IRAS Sky Survey Atlas: Explanatory Supplement (JPL Publ. 94-11; Pasadena: JPL)), using a computer vision algorithm that is unbiased with respect to source intensity. Our catalog is two-tiered: the selection criteria in the Galactic plane are based on the sensitivity limits of airborne polarimeters such as the proposed HALE instrument for SOFIA, and away from the plane the limits are dictated by the sensitivities of balloon-borne cosmic microwave background experiments, such as BOOMERanG and MAXIMA. Infrared detector technology is currently at the point where detecting the polarization of the interstellar cirrus is feasible, and we hope this catalog will assist any experimenter undertaking this task.
99. Bright nearby elliptical gal. Xshooter spectra
ID:
ivo://CDS.VizieR/J/A+A/621/A60
Title:
Bright nearby elliptical gal. Xshooter spectra
Short Name:
J/A+A/621/A60
Date:
21 Oct 2021
Publisher:
CDS
Description:
A new generation of spectral synthesis models has been developed in the recent years, but there is no matching -- in terms of quality and resolution -- set of template galaxy spectra for testing and refining the new models. Our main goal is to find and calibrate new near-infrared spectral indices along the Hubble sequence of galaxies which will be used to obtain additional constraints to the population analysis based on medium resolution integrated spectra of galaxies. Spectra of previously studied and well understood galaxies with relatively simple stellar populations (e.g., ellipticals or bulge dominated galaxies) are needed to provide a baseline data set for spectral synthesis models. X-Shooter spectra spanning the optical and infrared wavelength (350-2400nm) of bright nearby elliptical galaxies with resolving power R~4000-5400 were obtained. Heliocentric systemic velocity, velocity dispersion and Mg, Fe and H{beta} line-strength indices are presented. We present a library of very high quality spectra of galaxies covering a large range of age, metallicity and morphological type. Such as a dataset of spectra will be crucial to address important questions of the modern investigation concerning galaxy formation and evolution.
100. Brown dwarfs in the 2MASS Survey
ID:
ivo://CDS.VizieR/J/AJ/127/2856
Title:
Brown dwarfs in the 2MASS Survey
Short Name:
J/AJ/127/2856
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the discovery of seven new T dwarfs identified in the Two Micron All Sky Survey (Cat. <II/246>). Low-resolution (R~150) 0.8-2.5{mu}m spectroscopy obtained with the Infrared Telescope Facility (IRTF) SpeX instrument reveals the characteristic H_2_O and CH_4_ bands in the spectra of these brown dwarfs. Comparison with spectral standards observed with the same instrument enables us to derive classifications of T3 to T7 for the objects in this sample. Moderate-resolution (R~1200) near-infrared spectroscopy for a subset of these discoveries reveal K I line strengths consistent with previously observed trends with spectral type. Follow-up imaging observations provide proper-motion measurements for these sources, ranging from less than 0.1" to 1.55"/yr. One object, 2MASS 0034+0523, has a spectrophotometric distance placing it within 10pc of the Sun. This source also exhibits a depressed K-band peak reminiscent of the peculiar T dwarf 2MASS 0937+2931 and may be a metal-poor or old, high-mass brown dwarf. We also present low-resolution SpeX data for a set of M- and L-type dwarf, subdwarf, and giant comparison stars used to classify 59 additional candidates identified as background stars. These are primarily M5-M8.5 dwarfs, many exhibiting H I Pa^{gamma}^, but include three candidate ultracool M subdwarfs and one possible early-type L subdwarf.