- ID:
- ivo://CDS.VizieR/J/ApJS/176/301
- Title:
- Subaru/XMM-Newton deep survey IV. (SXDS)
- Short Name:
- J/ApJS/176/301
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present luminosity functions (LFs) and various properties of Ly{alpha} emitters (LAEs) at z=3.1, 3.7, and 5.7, in a 1deg^2^ sky of the Subaru/XMM-Newton Deep Survey (SXDS) Field. We obtain a photometric sample of 858 LAE candidates based on deep Subaru Suprime-Cam imaging data and a spectroscopic sample of 84 confirmed LAEs from Subaru FOCAS and VLT VIMOS spectroscopy in a survey volume of ~10^6^Mpc^3^ with a limiting Ly{alpha} luminosity of ~3x10^42^ergs/s. We derive the LFs of the Ly{alpha} and UV continuum (~1500{AA}) for each redshift, taking into account the statistical error and the field-to-field variation. We identify six LAEs with AGN activities from our spectra combined with VLA, Spitzer, and XMM-Newton data. Among the photometrically selected LAEs at z=3.1 and 3.7, only ~1% show AGN activities, while the brightest LAEs with logL(Ly{alpha})>~43.4-43.6ergs/s appear to always host AGNs. Our LAEs are bluer in UV-continuum color than dropout galaxies, suggesting lower extinction and/or younger stellar populations.
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- ID:
- ivo://CDS.VizieR/J/ApJS/176/1
- Title:
- Subaru/XMM-Newton deep survey (SXDS). II.
- Short Name:
- J/ApJS/176/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present multi-wave band optical imaging data obtained from observations of the Subaru/XMM-Newton Deep Survey (SXDS). The survey field, centered at RA=02:18:00, DE=-05:00:00, has been the focus of a wide range of multiwavelength observing programs spanning from X-ray to radio wavelengths. A large part of the optical imaging observations are carried out with Suprime-Cam on Subaru Telescope at Mauna Kea in the course of Subaru Telescope "Observatory Projects".
- ID:
- ivo://CDS.VizieR/J/ApJS/179/124
- Title:
- Subaru/XMM-Newton deep survey (SXDS) III.
- Short Name:
- J/ApJS/179/124
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the X-ray source catalog in the Subaru/XMM-Newton deep survey. A continuous area of 1.14deg^2^ centered at RA=02h18m and DE=-05{deg} is mapped by seven pointings with XMM-Newton covering the 0.2-10keV band. From the combined images of the EPIC pn and MOS cameras, we detect 866, 1114, 645, and 136 sources with sensitivity limits of 6x10^-16^, 8x10^-16^, 3x10^-15^, and 5x10^-15^ergs/cm^2^/s in the 0.5-2, 0.5-4.5, 2-10, and 4.5-10keV bands, respectively, with detection likelihood >=7 (corresponding to a confidence level of 99.91%). The catalog consists of 1245 sources in total including 32 extended-source candidates. The averaged logN-logS relations are in good agreement with previous results, bridging the flux range between Chandra deep surveys and brighter surveys.
- ID:
- ivo://CDS.VizieR/J/ApJ/839/23
- Title:
- Subdwarf A stars vs ELM WDs radial velocities
- Short Name:
- J/ApJ/839/23
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We address the physical nature of subdwarf A-type (sdA) stars and their possible link to extremely low mass (ELM) white dwarfs (WDs). The two classes of objects are confused in low-resolution spectroscopy. However, colors and proper motions indicate that sdA stars are cooler and more luminous, and thus larger in radius, than published ELM WDs. We demonstrate that surface gravities derived from pure hydrogen models suffer a systematic ~1dex error for sdA stars, likely explained by metal line blanketing below 9000K. A detailed study of five eclipsing binaries with radial velocity orbital solutions and infrared excess establishes that these sdA stars are metal-poor ~1.2M_{sun}_ main sequence stars with ~0.8M_{sun}_ companions. While WDs must exist at sdA temperatures, only ~1% of a magnitude-limited sdA sample should be ELM WDs. We conclude that the majority of sdA stars are metal-poor A-F type stars in the halo, and that recently discovered pulsating ELM WD-like stars with no obvious radial velocity variations may be SX Phe variables, not pulsating WDs.
18255. Subdwarfs in the SDSS
- ID:
- ivo://CDS.VizieR/J/AJ/128/426
- Title:
- Subdwarfs in the SDSS
- Short Name:
- J/AJ/128/426
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a spectroscopic analysis of nearly 8000 late-type dwarfs in the Sloan Digital Sky Survey. Using the H{alpha} emission line as an activity indicator, we investigate the fraction of active stars as a function of spectral type and find a peak near type M8, confirming previous results.
- ID:
- ivo://CDS.VizieR/J/A+A/644/A85
- Title:
- Sub-milliarcsecond imaging of 3C111
- Short Name:
- J/A+A/644/A85
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Flares in radio-loud active galactic nuclei (AGNs) are thought to be associated with the injection of fresh plasma into the compact jet base. Such flares are usually strongest and appear earlier at shorter radio wavelengths. Hence, very long baseline interferometry (VLBI) at millimeter (mm)-wavelengths is the best-suited technique for studying the earliest structural changes of compact jets associated with emission flares. Aims. We study the morphological changes of the parsec-scale jet in the nearby (z=0.049) gamma-ray bright radio galaxy 3C 111 following a flare that developed into a major radio outburst in 2007. We analyse three successive observations of 3C 111 at 86 GHz with the Global mm-VLBI Array (GMVA) between 2007 and 2008 which yield a very high angular resolution of ~45 muas. In addition, we make use of single-dish radio flux density measurements from the F-GAMMA and POLAMI programmes, archival single-dish and VLBI data. We resolve the flare into multiple plasma components with a distinct morphology resembling a bend in an otherwise remarkably straight jet. The flare-associated features move with apparent velocities of ~4.0c to ~4.5c and can be traced also at lower frequencies in later epochs. Near the base of the jet, we find two bright features with high brightness temperatures up to ~10^11^K, which we associate with the core and a stationary feature in the jet. The flare led to multiple new jet components indicative of a dynamic modulation during the ejection. We interpret the bend-like feature as a direct result of the outburst which makes it possible to trace the transverse structure of the jet. In this scenario, the components follow different paths in the jet stream consistent with expectations for a spine-sheath structure, which is not seen during intermediate levels of activity. The possibility of coordinated multiwavelength observations during a future bright radio flare in 3C 111 makes this source an excellent target for probing the radio-gamma-ray connection.
- ID:
- ivo://CDS.VizieR/J/ApJS/175/277
- Title:
- Submillimeter-Continuum SCUBA detections
- Short Name:
- J/ApJS/175/277
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the SCUBA Legacy Catalogues, two comprehensive sets of continuum maps (and catalogs) using data at 850 and 450um of the various astronomical objects obtained with the Submillimetre Common User Bolometer Array (SCUBA). The Fundamental Map Data Set contains data only where superior atmospheric opacity calibration data were available. The Extended Map Data Set contains data regardless of the quality of the opacity calibration. Each data set contains 1.2{deg}x1.2{deg} maps at locations where data existed in the JCMT archive, imaged using the matrix inversion method. The Fundamental Data Set is composed of 1423 maps at 850um and 1357 maps at 450um. The Extended Data Set is composed of 1547 maps at 850um. Neither data set includes high sensitivity, single-chop SCUBA maps of "cosmological fields" nor solar system objects. Each data set was used to determine a respective object catalogue, consisting of objects identified within the respective 850um maps using an automated identification algorithm. The Fundamental and Extended Map Object Catalogues contain 5061 and 6118 objects, respectively. Objects are named based on their respective J2000.0 position of peak 850um intensity. The catalogues provide for each object the respective maximum 850um intensity, estimates of total 850um flux and size, and tentative identifications from the SIMBAD Database. Where possible, the catalogues also provide for each object its maximum 450um intensity and total 450um flux and flux ratios.
- ID:
- ivo://CDS.VizieR/J/A+A/616/A107
- Title:
- (Sub)millimeter RRL in high-mass star-forming clumps
- Short Name:
- J/A+A/616/A107
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Previous radio recombination line (RRL) observations of dust clumps identified in the APEX Telescope Large Area Survey of the Galaxy (ATLASGAL) have led to the detection of a large number of RRLs in the 3mm range. Here, we aim to study their excitation with shorter wavelength (sub)millimeter radio recombination line (submm-RRL) observations. We made observations of submm-RRLs with low principal quantum numbers (n<=30) using the APEX 12m telescope, toward 104 HII regions associated with massive dust clumps from ATLASGAL. The observations covered the H25{alpha}, H28{alpha}, and H35{beta} transitions. Toward a small subsample the H26{alpha}, H27{alpha}, H29{alpha}, and H30{alpha} lines were observed to avoid contamination by molecular lines at adjacent frequencies. We have detected submm-RRLs (signal-to-noise >=3{sigma}) from compact HII regions embedded within 93 clumps. The submm-RRLs are approximately a factor of two brighter than the mm-RRLs and consistent with optically thin emission in local thermodynamic equilibrium (LTE). The average ratio (0.31) of the measured H35{beta}/H28{alpha} fluxes is close to the LTE value of 0.28. No indication of RRL maser emission has been found. The Lyman photon flux, bolometric, and submm-RRL luminosities toward the submm-RRL detected sources present significant correlations. The trends of dust temperature and the ratio of bolometric luminosity to clump mass, L_bol_/M_clump_, indicate that the HII regions are related to L_bol_/M_clump_, indicate that the HII regions are related to the most massive and luminous clumps. By estimating the production rate of ionizing photons, Q, from the submm-RRL flux, we find that the Q(H28{alpha}) measurements provide estimates of the Lyman continuum photon flux consistent with those determined from 5GHz radio continuum emission. Six RRL sources show line profiles that are a combination of a narrow and a broad Gaussian feature. The broad features are likely associated with high-velocity ionized flows. We have detected submm-RRLs toward 93 ATLASGAL clumps. Six RRL sources have high-velocity RRL components likely driven by high-velocity ionized flows. Their observed properties are consistent with thermal emission that correlates well with the Lyman continuum flux of the HII regions. The sample of HII regions with mm/submm-RRL detections probes, in our Galaxy, luminous clumps (L_bol_>10^4^L_{sun}_) with high L_bol_/M_clump_. We also provide suitable candidates for further studies of the morphology and kinematics of embedded, compact HII regions with the Atacama Large Millimeter/submillimeter Array (ALMA).
- ID:
- ivo://CDS.VizieR/J/A+A/601/A50
- Title:
- Sub-millimeter spectra of 2-hydroxyacetonitrile
- Short Name:
- J/A+A/601/A50
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Recent experimental works have studied the possible formation of hydroxyacetonitrile on astrophysical grains. It was formed from hydrogen cyanide (HCN) and formaldehyde (H_2_CO) in the presence of water under interstellar medium (ISM) conditions. Because these precursor molecules are abundant, hydroxyacetonitrile is an excellent target for interstellar detection. Previous studies of the rotational spectra were limited to 40GHz, resulting in an inaccurate line list when predicted up to the millimeter-wave range. We measured and analyzed its spectra up to 600GHz to enable is searches using cutting-edge millimeter and submillimeter observatories. The molecule 2-hydroxyacetonitrile exhibits large amplitude motion that is due to the torsion of the hydroxyl group. The analysis of the spectra was made using the RAS formalism available in the SPFIT program with Watson's S-reduction Hamiltonians. The submillimeter spectra of hydroxyacetonitrile, an astrophysically interesting molecule, were analyzed. More than 5000 lines were fitted with quantum number values reaching 75 and 25 for J and K_a_, respectively. An accurate line list and partition function were provided. A search for hydroxyacetonitrile in publicly available GBT PRIMOS project, IRAM 30m, and Herschel HEXOS observations of the Sgr B2(N) high-mass star-forming region resulted in a non-detection; upper limits to the column density were determined.
- ID:
- ivo://CDS.VizieR/J/A+A/543/A46
- Title:
- Submillimeter spectrum of HCOOCD_2_H
- Short Name:
- J/A+A/543/A46
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Astronomical surveys of interstellar molecules, such as those that will be available with the very sensitive ALMA telescope, require preliminary laboratory investigations of the microwave and submillimeter-wave spectra of new molecular species to identify these in the interstellar media. We build a linelist that should allow us to detect HCOOCD_2_H, provided it is present in the interstellar media in a suitable concentration.