- ID:
- ivo://CDS.VizieR/J/AJ/156/178
- Title:
- NIR transmission spectra of TRAPPIST-1 planets
- Short Name:
- J/AJ/156/178
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The seven approximately Earth-sized transiting planets in the TRAPPIST-1 system provide a unique opportunity to explore habitable- and nonhabitable-zone small planets within the same system. Its habitable-zone exoplanets - due to their favorable transit depths - are also worlds for which atmospheric transmission spectroscopy is within reach with the Hubble Space Telescope (HST) and James Webb Space Telescope (JWST). We present here an independent reduction and analysis of two HST Wide Field Camera 3 (WFC3) near-infrared transit spectroscopy data sets for six planets (b through g). Utilizing our physically motivated detector charge-trap correction and a custom cosmic-ray correction routine, we confirm the general shape of the transmission spectra presented by de Wit et al. (2016Natur.537...69D). Our data reduction approach leads to a 25% increase in the usable data and reduces the risk of confusing astrophysical brightness variations (e.g., flares) with instrumental systematics. No prominent absorption features are detected in any individual planet's transmission spectra; by contrast, the combined spectrum of the planets shows a suggestive decrease around 1.4 {mu}m similar to an inverted water absorption feature. Including transit depths from K2, the SPECULOOS-South Observatory, and Spitzer, we find that the complete transmission spectrum is fully consistent with stellar contamination owing to the transit light source effect. These spectra demonstrate how stellar contamination can overwhelm planetary absorption features in low-resolution exoplanet transit spectra obtained by HST and JWST and also highlight the challenges in combining multi-epoch observations for planets around rapidly rotating spotted stars.
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702. NOIRCAT sources
- ID:
- ivo://CDS.VizieR/J/MNRAS/399/2264
- Title:
- NOIRCAT sources
- Short Name:
- J/MNRAS/399/2264
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the Northern HIPASS (HI Parkes All-Sky Survey) Optical/Infrared Catalogue (NOIRCAT), an optical/near-infrared (NIR) counterpart to the Northern HIPASS Catalogue (NHICAT). Of the 1002 sources in NHICAT, 655 (66 per cent) have optical counterparts with matching optical velocities. A further 85 (8 per cent) sources have optical counterparts with matching velocities from previous radio emission-line surveys.
- ID:
- ivo://CDS.VizieR/J/A+A/384/473
- Title:
- O, B and Be stars equivalent widths
- Short Name:
- J/A+A/384/473
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an atlas of spectra of O- and B-type stars, obtained with the Short Wavelength Spectrometer (SWS) during the Post-Helium program of the Infrared Space Observatory (ISO). This program is aimed at extending the Morgan & Keenan (1973ARA&A..11...29M) classification scheme into the near-infrared. Later type stars will be discussed in a separate publication. The observations consist of 57 SWS Post-Helium spectra from 2.4 to 4.1{mu}m, supplemented with 10 spectra acquired during the nominal mission with a similar observational setting. For B-type stars, this sample provides ample spectral coverage in terms of subtype and luminosity class. For O-type stars, the ISO sample is coarse and therefore is complemented with 8 UKIRT L'-band observations. In terms of the presence of diagnostic lines, the L'-band is likely the most promising of the near-infrared atmospheric windows for the study of the physical properties of B stars. Specifically, this wavelength interval contains the Br{alpha}, Pf{gamma}, and other Pfund lines which are probes of spectral type, luminosity class and mass loss. Here, we present simple empirical methods based on the lines present in the 2.4 to 4.1{mu}m interval that allow the determination of i) the spectral type of B dwarfs and giants to within two subtypes; ii) the luminosity class of B stars to within two classes; iii) the mass-loss rate of O stars and B supergiants to within 0.25dex.
- ID:
- ivo://CDS.VizieR/J/A+AS/125/419
- Title:
- Obscured AGB in Magellanic Clouds. I.
- Short Name:
- J/A+AS/125/419
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have selected 198 IRAS sources in the Large Magellanic Cloud, and 11 in the Small Magellanic Cloud, which are the best candidates to be mass-loosing AGB stars (or possibly post-AGB stars). We used the catalogues of Schwering & Israel (1990, Cat. II/181) and Reid et al. (1990, Cat. J/ApJ/348/98). They are based on the IRAS pointed observations and have lower detection limits than the Point Source Catalogue. We also made cross-identifications between IRAS sources and optical catalogues.
- ID:
- ivo://CDS.VizieR/J/ApJ/740/37
- Title:
- Obscured AGN at z~0.5-1 in the CDFS
- Short Name:
- J/ApJ/740/37
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We identify a numerically significant population of heavily obscured AGNs at z~0.5-1 in the Chandra Deep Field-South (CDF-S) and Extended Chandra Deep Field-South by selecting 242 X-ray undetected objects with infrared-based star-formation rates (SFRs) substantially higher (a factor of 3.2 or more) than their SFRs determined from the UV after correcting for dust extinction. An X-ray stacking analysis of 23 candidates in the central CDF-S region using the 4Ms Chandra data reveals a hard X-ray signal with an effective power-law photon index of {Gamma}=0.6^+0.3^_-0.4_, indicating a significant contribution from obscured AGNs. Based on Monte Carlo simulations, we conclude that 74%+/-25% of the selected galaxies host obscured AGNs, within which ~95% are heavily obscured and ~80% are Compton-thick (CT; N_H_>1.5x10^24^cm^-2^).
- ID:
- ivo://CDS.VizieR/J/A+A/556/A114
- Title:
- Obscured AGNs in XMM deep survey in CDF-S
- Short Name:
- J/A+A/556/A114
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Accretion onto supermassive black holes is believed to occur mostly in obscured active galactic nuclei (AGN). Such objects are proving rather elusive in surveys of distant galaxies, including those at X-ray energies. Our main goal is to determine whether the revised IRAC criteria of Donley et al. (2012ApJ...748..142D; objects with an infrared (IR) power-law spectral shape), are effective at selecting X-ray type-2 AGN (i.e., absorbed N_H_>10^22^cm^-2^). We present the results from the X-ray spectral analysis of 147 AGN selected by cross-correlating the highest spectral quality ultra-deep XMM-Newton and the Spitzer/IRAC catalogues in the Chandra Deep Field South. Consequently it is biased towards sources with high S/N X-ray spectra. In order to measure the amount of intrinsic absorption in these sources, we adopt a simple X-ray spectral model that includes a power-law modified by intrinsic absorption at the redshift of each source and a possible soft X-ray component.
- ID:
- ivo://CDS.VizieR/J/ApJ/669/446
- Title:
- Observations of SiO masers
- Short Name:
- J/ApJ/669/446
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of SiO millimeter line observations of a sample of known SiO maser sources covering a wide dust temperature range. A cold part of the sample was selected from the SiO maser sources found in our recent SiO maser survey of cold dusty objects. The aim of the present research is to investigate the causes of the correlation between infrared colors and SiO maser intensity ratios among different transition lines. In particular, the correlation between infrared colors and SiO maser intensity ratio among the J=1-0 v=1, 2, and 3 lines are our main concern in this paper. We observed in total 75 SiO maser sources with the Nobeyama 45m telescope quasi-simultaneously in the SiO J=1-0 v=0, 1, 2, 3, 4 and J=2-1 v=1, 2 lines. We also observed the sample in the ^29^SiO J=1-0 v=0 and J=2-1 v=0 lines, ^30^SiO J=1-0 v=0 line, and the H_2_O 61,6-52,3 line.
- ID:
- ivo://CDS.VizieR/J/ApJ/822/L5
- Title:
- Observed red supergiants in the inner Galaxy
- Short Name:
- J/ApJ/822/L5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this Letter, we present a search for Galactic red supergiant stars (RSGs) in the direction of the inner Galaxy. A total of 94 targets selected from the 2MASS (Cat. VII/233) and GLIMPSE I North (Benjamin et al. 2003, Cat. II/293; Churchwell et al. 2009PASP..121..213C) catalogs - via their blue extinction-free Q1 and Q2 colors - were spectroscopically observed at infrared wavelengths (in the H- and K-bands at R~1000), and an extraordinary high detection rate of RSGs (>61%) was found. We identified spectroscopically 58 RSGs, based on their flat continua and large equivalent widths of the CO-band at 2.293 {mu}m (EW>45 {AA}). This increase corresponds to about 25% of previously known RSGs in the Galactic region 10{deg}<l<60{deg}, -1.1{deg}<b<1.1{deg}. In order to confirm the location of the new RSGs in the inner Galaxy, distances were estimated for a subsample of 47 stars with the clump method and found to range from 3.6+/-0.4 to 8.6+/-0.7 kpc. The large new sample will allow us to investigate Galactic metallicity gradients as a function of galactocentric distances and azimuthal angles. Such information is currently an highly disputed issue to constrain models of Galaxy formation and evolution.
- ID:
- ivo://CDS.VizieR/J/AcA/43/209
- Title:
- OB stars extinction based in IR photometry
- Short Name:
- J/AcA/43/209
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The paper presents an extensive survey of interstellar extinction curves derived from the near IR photometric measurements of early type stars belonging to our Galaxy. This survey is more extensive and deeper than any other one, based on spectral data. The IR magnitudes of about 500 O and B type stars with E(B-V)>=0.05 were selected from literature. The IR color excesses are determined with the aid of "artificial standards". The results indicate that the extinction law changes from place to place. The mean galactic extinction curve in the near IR is very similar in different directions and changes very little from the value R=3.10+/-0.05 obtained in this paper.
- ID:
- ivo://CDS.VizieR/J/AJ/159/199
- Title:
- OCCAM. IV. Open cluster abundances using APOGEE DR16
- Short Name:
- J/AJ/159/199
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Open Cluster Chemical Abundances and Mapping (OCCAM) survey aims to constrain key Galactic dynamical and chemical evolution parameters by the construction of a large, comprehensive, uniform, infrared-based spectroscopic data set of hundreds of open clusters. This fourth contribution from the OCCAM survey presents analysis using Sloan Digital Sky Survey/APOGEE DR16 of a sample of 128 open clusters, 71 of which we designate to be "high quality" based on the appearance of their color-magnitude diagram. We find the APOGEE DR16 derived [Fe/H] abundances to be in good agreement with previous high-resolution spectroscopic open cluster abundance studies. Using the high-quality sample, we measure Galactic abundance gradients in 16 elements, and find evolution of some of the [X/Fe] gradients as a function of age. We find an overall Galactic [Fe/H] versus Rgc gradient of -0.068{+-}0.001dex/kpc over the range of 6<Rgc<13.9kpc; however, we note that this result is sensitive to the distance catalog used, varying as much as 15%. We formally derive the location of a break in the [Fe/H] abundance gradient as a free parameter in the gradient fit for the first time. We also measure significant Galactic gradients in O, Mg, S, Ca, Mn, Cr, Cu, Na, Al, and K, some of which are measured for the first time. Our large sample allows us to examine four well-populated age bins in order to explore the time evolution of gradients for a large number of elements and comment on possible implications for Galactic chemical evolution and radial migration.
