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61. Ackermann red stars
ID:
ivo://CDS.VizieR/II/260
Title:
Ackermann red stars
Short Name:
II/260
Date:
21 Oct 2021
Publisher:
CDS
Description:
In the late 1960s Gerhard Ackermann published two lists of extremely red stars (1968ZA.....69..130A and 1970A&A.....8..315A), including what appeared to be reliable spectral classifications for a few hundred stars. The two published papers provide details of the observing and analysis, made between June and October 1968 at the Heidelberg observatory with the 25cm f/3.6 Schmidt camera together with a 10-degree UBK7 prism yielding a dispersion of 3500 {AA}/mm at the atmospheric A band (7700{AA}). Exposures on ammonia-hypersensitized Kodak I-N emulsion + RG665 filter were obtained along with direct plates on I-N emulsion as well as 103a-E + OG550, totalling 101 exposures in all. The spectra were classified by following the precepts of Cameron & Nassau (1955ApJ...122..177C) and Nassau & Velghe (1964ApJ...139..190N). Ackermann initiated photoelectric observations at I and K, but obviously the Heidelberg weather was not conducive to pursuing this. Because the calibration of the photometry on the direct plates was by necessity rather crude, Ackermann's photometric results are not reported here -- the procedures used were sufficient to identify the reddest stars, but not for much else. Approximate V magnitudes were added for all the stars -- for the most part these are merely averages of the photo-blue and -red magnitudes in both GSC-2.2 and USNO-B1.0, but their zero-point and scale should be reliable at the few-tenths magnitude level in this range. Coordinates were drawn from either UCAC2 or 2MASS depending mainly on Declination, since UCAC2 extends only to about +40 Dec in this area. The UCAC2 positions should be good to better than 0.1", and those from 2MASS to 0.2". In a few cases, such as gross overexposure in 2MASS, positions are from various Schmidt survey catalogues, as indicated with each entry. The first 13 stars of the catalog come from the concluding volume of the ZA paper; in the 1970 paper, Ackermann refers to these stars using the acronym HDK, which is adopted here. The published table gave rather rough arcminute-precision positions (for equinox 1965). Star 6 was recovered 1 degree east of the nominal place, and identified with the variable star WX CMi. Along with the positions and IDs, the table shows V magnitudes and the spectral types given in the original paper. Some of the stars are within the region covered by the ASAS-3 survey, so reliable V magnitudes are available along with beautiful lightcurves. Ackermann's second much longer list contains rough photometry from the POSS-I prints for some 400 very red stars in the Cygnus starcloud, and for 254 of these spectral types were also determined. The stars without spectral classifications comprise a diverse group including both red/reddened late-type stars and greatly obscured hotter stars, but no real astrophysical information is given for any of them beyond sheer redness -- these stars are omitted from the catalog. In consultation with Prof Ackermann, the following changes have been made to the spectral types: for stars shown in the original table with a hyphen between two types (e.g. M5-M6), this was to show that the type was uncertain to that degree (i.e. M5 or M6), for which the 'slash' notation of Nancy Houk was preferred, and thus M5-M6 becomes M5/6. One star, 78-0-144, exhibited a range in types, and it is shown as M7-M9. Ackermann also indicated a number of stars as being of very-late type with VO present (separable from the A-band), but where the star was too faint to classify accurately. He agrees these are likely to be in the range M7 to M9, and again these are shown in the slash-style notation as M7/9:, with the colon added to indicate uncertainty since the types were not explicit in the original, and sometimes a question mark for those already marked as uncertain in the original. These changes were made so that machine parsing schemes will be better able to handle the classifications.
62. ACO 1825 and AC 114 EROs photometry
ID:
ivo://CDS.VizieR/J/A+A/477/55
Title:
ACO 1825 and AC 114 EROs photometry
Short Name:
J/A+A/477/55
Date:
21 Oct 2021
Publisher:
CDS
Description:
We study the properties and nature of extremely red galaxies (ERO, R-K>=5.6) found behind two lensing clusters and compare them with other known galaxy populations. New HST/ACS, Spitzer (IRAC and MIPS), and Chandra/ACIS observations of the two lensing clusters Abell 1835 and AC 114 (ACCG 114) have been obtained, combined with our earlier optical and near-IR observations and used to study EROs in these deep fields.
63. A1367, Coma and Virgo r' photometry
ID:
ivo://CDS.VizieR/J/A+A/401/471
Title:
A1367, Coma and Virgo r' photometry
Short Name:
J/A+A/401/471
Date:
21 Oct 2021
Publisher:
CDS
Description:
Optical spectroscopy of 93 galaxies, 60 projected in the direction of Abell 1367, 21 onto the Coma cluster and 12 on Virgo, is reported. The targets were selected because they were detected in previous H{alpha}, UV or r' surveys. The present observations bring to 100% the redshift completeness of H{alpha} selected galaxies in the Coma region and to 75% in Abell 1367. All observed galaxies except one show H{alpha} emission and belong to the clusters. This confirms previous determinations of the H{alpha} luminosity function of the two clusters that were based on the assumption that all H{alpha} detected galaxies were cluster members. Using the newly obtained data we re-determine the UV luminosity function of Coma and we compute for the first time the UV luminosity function of A1367.
64. A combined Chandra & LAMOST study of stellar activity
ID:
ivo://CDS.VizieR/J/ApJ/871/193
Title:
A combined Chandra & LAMOST study of stellar activity
Short Name:
J/ApJ/871/193
Date:
21 Oct 2021
Publisher:
CDS
Description:
We probed stellar X-ray activity over a wide range of stellar parameters, using Chandra and Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) data. We measured the X-ray-to-bolometric luminosity ratio (R_X_=L_X_/L_bol_) for 484 main-sequence stars and found a bimodal distribution for G and K types. We interpret this bimodality as evidence of two subpopulations with different coronal temperatures, which are caused by different coronal heating rates. Using the metallicity and velocity information, we find that both of the subpopulations are mostly located in the thin disk. We find no trend of R_X_ with stellar age for stars older than ~4Gyr; there is a trough in the R_X_ versus age distribution, with the lowest range of R_X_ appearing at ages around 2Gyr. We then examined the correlation between R_X_ and R_H{alpha}_ (proxy of chromospheric activity): we find that the two quantities are well correlated, as found in many earlier studies. Finally, we selected a sample of 12 stars with X-ray flares and studied the light-curve morphology of the flares. The variety of flare profiles and timescales observed in our sample suggests the contribution of different processes of energy release.
65. A complete sample of broad-line AGN from SDSS-DR7
ID:
ivo://CDS.VizieR/J/ApJS/243/21
Title:
A complete sample of broad-line AGN from SDSS-DR7
Short Name:
J/ApJS/243/21
Date:
21 Oct 2021
Publisher:
CDS
Description:
A new, complete sample of 14584 broad-line active galactic nuclei (AGNs) at z<0.35 is presented, which are uncovered homogeneously from the complete database of galaxies and quasars observed spectroscopically in the Sloan Digital Sky Survey Seventh Data Release. The stellar continuum is properly removed for each spectrum with significant host absorption line features, and careful analyses of the emission line spectra, particularly in the H{alpha} and H{beta} wavebands, are carried out. The broad Balmer emission line, particularly H{alpha}, is used to indicate the presence of an AGN. The broad H{alpha} lines have luminosities in a range of 10^38.5^-10^44.3^erg/s, and line widths (FWHMs) of 500-34000km/s. The virial black hole masses, estimated from the broad-line measurements, span a range of 10^5.1^-10^10.3^M_{sun}_, and the Eddington ratios vary from -3.3 to 1.3 in logarithmic scale. Other quantities such as multiwavelength photometric properties and flags denoting peculiar line profiles are also included in this catalog. We describe the construction of this catalog and briefly discuss its properties. The catalog is publicly available online. This homogeneously selected AGN catalog, along with the accurately measured spectral parameters, provides the most updated, largest AGN sample data, which will enable further comprehensive investigations of the properties of the AGN population in the low-redshift universe.
66. A composite HII region luminosity function
ID:
ivo://CDS.VizieR/J/A+A/459/L13
Title:
A composite HII region luminosity function
Short Name:
J/A+A/459/L13
Date:
21 Oct 2021
Publisher:
CDS
Description:
Statistical properties of HII region populations in disk galaxies yield important clues to the physics of massive star formation. We present a set of HII region catalogues and luminosity functions for a sample of 56 spiral galaxies in order to derive the most general form of their luminosity function. HII region luminosity functions were derived for individual galaxies which, after photometric calibration, were summed to form a total luminosity function comprising 17797 HII regions from 53 galaxies.
67. A comprehensive analysis of Spitzer supernovae
ID:
ivo://CDS.VizieR/J/ApJS/241/38
Title:
A comprehensive analysis of Spitzer supernovae
Short Name:
J/ApJS/241/38
Date:
21 Oct 2021
Publisher:
CDS
Description:
The mid-infrared (mid-IR) wavelength regime offers several advantages for following the late-time evolution of supernovae (SNe). First, the peaks of the SN spectral energy distributions shift toward longer wavelengths, following the photospheric phase. Second, mid-IR observations suffer less from effects of interstellar extinction. Third, and perhaps most important, the mid-IR traces dust formation and circumstellar interaction at late times (>100 days) after the radioactive ejecta component fades. The Spitzer Space Telescope has provided substantial mid-IR observations of SNe since its launch in 2003. More than 200 SNe have been targeted, but there are even more SNe that have been observed serendipitously. Here we present the results of a comprehensive study based on archival Spitzer/IRAC images of more than 1100 SN positions; from this sample, 119 SNe of various subclasses have been detected, including 45 SNe with previously unpublished mid-IR photometry. The photometry reveals significant amounts of warm dust in some cases. We perform an in-depth analysis to constrain the origin and heating mechanism of the dust, and present the resulting statistics.
68. A3COSMOS. I. ALMA continuum photometry catalogs
ID:
ivo://CDS.VizieR/J/ApJS/244/40
Title:
A3COSMOS. I. ALMA continuum photometry catalogs
Short Name:
J/ApJS/244/40
Date:
21 Oct 2021
Publisher:
CDS
Description:
The rich information on (sub)millimeter dust continuum emission from distant galaxies in the public Atacama Large Millimeter/submillimeter Array (ALMA) archive is contained in thousands of inhomogeneous observations from individual PI-led programs. To increase the usability of these data for studies deepening our understanding of galaxy evolution, we have developed automated mining pipelines for the ALMA archive in the COSMOS field (A3COSMOS) that efficiently exploit the available information for large numbers of galaxies across cosmic time and keep the data products in sync with the increasing public ALMA archive: (a) a dedicated ALMA continuum imaging pipeline, (b) two complementary photometry pipelines for both blind source extraction and prior source fitting, (c) a counterpart association pipeline utilizing the multiwavelength data available (including quality assessment based on machine-learning techniques), (d) an assessment of potential (sub)millimeter line contribution to the measured ALMA continuum, and (e) extensive simulations to provide statistical corrections to biases and uncertainties in the ALMA continuum measurements. Application of these tools yields photometry catalogs with ~1000 (sub)millimeter detections (spurious fraction ~8%-12%) from over 1500 individual ALMA continuum images. Combined with ancillary photometric and redshift catalogs and the above quality assessments, we provide robust information on redshift, stellar mass, and star formation rate for ~700 galaxies at redshifts 0.5-6 in the COSMOS field (with undetermined selection function). The ALMA photometric measurements and galaxy properties are released publicly within our blind extraction, prior fitting, and galaxy property catalogs, plus the images.
69. ACRONYM. III. Candidate young low-mass stars
ID:
ivo://CDS.VizieR/J/AJ/157/234
Title:
ACRONYM. III. Candidate young low-mass stars
Short Name:
J/AJ/157/234
Date:
21 Oct 2021
Publisher:
CDS
Description:
Young, low-mass stars in the solar neighborhood are vital for completing the mass function for nearby, young coeval groups, establishing a more complete census for evolutionary studies, and providing targets for direct-imaging exoplanet and/or disk studies. We present properties derived from high-resolution optical spectra for 336 candidate young nearby, low-mass stars. These include measurements of radial velocities and age diagnostics such as H{alpha} and Li {lambda}6707 equivalent widths. Combining our radial velocities with astrometry from Gaia DR2 (Cat. I/345), we provide full 3D kinematics for the entire sample. We combine the measured spectroscopic youth information with additional age diagnostics (e.g., X-ray and UV fluxes, color-magnitude diagram positions) and kinematics to evaluate potential membership in nearby, young moving groups and associations. We identify 77 objects in our sample as bona fide members of 10 different moving groups, 14 of which are completely new members or have had their group membership reassigned. We also reject 44 previously proposed candidate moving group members. Furthermore, we have newly identified or confirmed the youth of numerous additional stars that do not belong to any currently known group and find 69 comoving systems using Gaia DR2 astrometry. We also find evidence that the Carina association is younger than previously thought, with an age similar to the {beta} Pictoris moving group (~22 Myr).
70. ACRONYM II. The {beta} Pictoris Moving Group
ID:
ivo://CDS.VizieR/J/AJ/154/69
Title:
ACRONYM II. The {beta} Pictoris Moving Group
Short Name:
J/AJ/154/69
Date:
21 Oct 2021
Publisher:
CDS
Description:
We confirm 66 low-mass stellar and brown dwarf systems (K7-M9) plus 19 visual or spectroscopic companions of the {beta} Pictoris moving group (BPMG). Of these, 41 are new discoveries, increasing the known low-mass members by 45%. We also add four objects to the 14 known with masses predicted to be less than 0.07 M_{sun}_. Our efficient photometric + kinematic selection process identified 104 low-mass candidates, which we observed with ground-based spectroscopy. We collected infrared observations of the latest spectral types (>M5) to search for low-gravity objects. These and all <M5 candidates were observed with high-resolution optical spectrographs to measure the radial velocities and youth indicators, such as lithium absorption and H{alpha} emission, needed to confirm BPMG membership, achieving a 63% confirmation rate. We also compiled the most complete census of BPMG membership, with which we tested the efficiency and false-membership assignments using our selection and confirmation criteria. Using the new census, we assess a group age of 22+/-6 Myr, consistent with past estimates. With the now-densely sampled lithium depletion boundary, we resolve the broadening of the boundary by either an age spread or astrophysical influences on lithium-burning rates. We find that 69% of the now-known members with AFGKM primaries are M stars, nearing the expected value of 75%. However, the new initial mass function for the BPMG shows a deficit of 0.2-0.3 M_{sun}_ stars by a factor of ~2. We expect that the AFGK census of the BPMG is also incomplete, probably due to biases of searches toward the nearest stars.