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491. Compact groups of galaxies from SDSS-DR12 (MLCG)
ID:
ivo://CDS.VizieR/J/ApJS/225/23
Title:
Compact groups of galaxies from SDSS-DR12 (MLCG)
Short Name:
J/ApJS/225/23
Date:
21 Oct 2021
Publisher:
CDS
Description:
We apply a friends-of-friends algorithm to an enhanced SDSS DR12 spectroscopic catalog, including redshift from the literature to construct a catalog of 1588 N>=3 compact groups of galaxies containing 5178 member galaxies and covering the redshift range 0.01<z<0.19. This catalog contains 18 times as many systems and reaches 3 times the depth of the similar catalog of Barton et al. (1996AJ....112..871B). We construct catalogs from both magnitude-limited and volume-limited galaxy samples. Like Barton et al. we omit the frequently applied isolation criterion in the compact group selection algorithm. Thus the groups selected by fixed projected spatial and rest-frame line-of-sight velocity separation produce a catalog of groups with a redshift-independent median size. In contrast to previous catalogs, the enhanced SDSS DR12 catalog (including galaxies with r<14.5) includes many systems with z<~0.05. The volume-limited samples are unique to this study. The compact group candidates in these samples have a median stellar mass independent of redshift. Groups with velocity dispersion <~100km/s show abundant evidence for ongoing dynamical interactions among the members. The number density of the volume-limited catalogs agrees with previous catalogs at the lowest redshifts but decreases as the redshift increases. The SDSS fiber placement constraints limit the catalog's completeness. In spite of this issue, the volume-limited catalogs provide a promising basis for detailed spatially resolved probes of the impact of galaxy-galaxy interactions within similar dense systems over a broad redshift range.
492. Compact groups of galaxies in SDSS & LAMOST. I.
ID:
ivo://CDS.VizieR/J/ApJS/246/12
Title:
Compact groups of galaxies in SDSS & LAMOST. I.
Short Name:
J/ApJS/246/12
Date:
21 Oct 2021
Publisher:
CDS
Description:
A compact group (CG) is a kind of special galaxy system where the galaxy members are separated at distances of the order of galaxy size. The strong interaction between the galaxy members makes CGs ideal labs for studying the environmental effects on galaxy evolution. The traditional photometric selection algorithm biases against the CG candidates at low redshifts, while the spectroscopic identification technique is affected by the spectroscopic incompleteness of sample galaxies and typically biases against the high redshift candidates. In this study, we combine these two methods and select CGs in the main galaxy sample of the Sloan Digital Sky Survey, where we also have taken the advantages of the complementary redshift measurements from the LAMOST spectral and GAMA surveys. We have obtained the largest and most complete CG samples to date. Our samples include 6144 CGs and 8022 CG candidates, which are unique in the studies of the nature of the CGs and the evolution of the galaxies inside.
493. Companions to nearby stars from Pan-STARRS 1
ID:
ivo://CDS.VizieR/J/ApJ/792/119
Title:
Companions to nearby stars from Pan-STARRS 1
Short Name:
J/ApJ/792/119
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the discovery of 57 wide (>5'') separation, low-mass (stellar and substellar) companions to stars in the solar neighborhood identified from Pan-STARRS 1 (PS1) data and the spectral classification of 31 previously known companions. Our companions represent a selective subsample of promising candidates and span a range in spectral type of K7-L9 with the addition of one DA white dwarf. These were identified primarily from a dedicated common proper motion search around nearby stars, along with a few as serendipitous discoveries from our Pan-STARRS 1 brown dwarf search. Our discoveries include 23 new L dwarf companions and one known L dwarf not previously identified as a companion. The primary stars around which we searched for companions come from a list of bright stars with well-measured parallaxes and large proper motions from the Hipparcos catalog (8583 stars, mostly A-K dwarfs) and fainter stars from other proper motion catalogs (79170 stars, mostly M dwarfs). We examine the likelihood that our companions are chance alignments between unrelated stars and conclude that this is unlikely for the majority of the objects that we have followed-up spectroscopically. We also examine the entire population of ultracool (>M7) dwarf companions and conclude that while some are loosely bound, most are unlikely to be disrupted over the course of ~10 Gyr. Our search increases the number of ultracool M dwarf companions wider than 300 AU by 88% and increases the number of L dwarf companions in the same separation range by 82%. Finally, we resolve our new L dwarf companion to HIP 6407 into a tight (0.13'', 7.4 AU) L1+T3 binary, making the system a hierarchical triple. Our search for these key benchmarks against which brown dwarf and exoplanet atmosphere models are tested has yielded the largest number of discoveries to date.
494. Comparative modelling of cool giants spectra
ID:
ivo://CDS.VizieR/J/A+A/547/A108
Title:
Comparative modelling of cool giants spectra
Short Name:
J/A+A/547/A108
Date:
21 Oct 2021
Publisher:
CDS
Description:
Our ability to extract information from the spectra of stars depends on reliable models of stellar atmospheres and appropriate techniques for spectral synthesis. The corresponding paper aims to compare a wide variety of model codes and strategies for the analysis of stellar spectra that are available today. The online tables list spectral lines used during the analysis together with the basic line parameters.
495. Comparison of IUE and CALSPEC SEDs for 6 WDs
ID:
ivo://CDS.VizieR/J/AJ/155/162
Title:
Comparison of IUE and CALSPEC SEDs for 6 WDs
Short Name:
J/AJ/155/162
Date:
21 Oct 2021
Publisher:
CDS
Description:
A collection of spectral energy distributions (SEDs) is available in the Hubble Space Telescope (HST) CALSPEC database that is based on calculated model atmospheres for pure hydrogen white dwarfs (WDs). A much larger set (~100000) of UV SEDs covering the range (1150-3350 {AA}) with somewhat lower quality are available in the IUE database. IUE low-dispersion flux distributions are compared with CALSPEC to provide a correction that places IUE fluxes on the CALSPEC scale. While IUE observations are repeatable to only 4%-10% in regions of good sensitivity, the average flux corrections have a precision of 2%-3%. Our re-calibration places the IUE flux scale on the current UV reference standard and is relevant for any project based on IUE archival data, including our planned comparison of GALEX to the corrected IUE fluxes. IUE SEDs may be used to plan observations and cross-calibrate data from future missions, so the IUE flux calibration must be consistent with HST instrumental calibrations to the best possible precision.
496. Comparison of Lick indexes
ID:
ivo://CDS.VizieR/J/MNRAS/406/165
Title:
Comparison of Lick indexes
Short Name:
J/MNRAS/406/165
Date:
21 Oct 2021
Publisher:
CDS
Description:
Stellar population models of absorption-line indices are an important tool for the analysis of stellar population spectra. They are most accurately modelled through empirical calibrations of absorption-line indices with the stellar parameters such as effective temperature, metallicity and surface gravity, which are the so-called fitting functions. Here we present new empirical fitting functions for the 25 optical Lick absorption-line indices based on the new stellar library Medium resolution INT Library of Empirical Spectra (MILES). The major improvements with respect to the Lick/IDS library are the better sampling of stellar parameter space, a generally higher signal-to-noise ratio and a careful flux calibration. In fact, we find that errors on individual index measurements in MILES are considerably smaller than in Lick/IDS. Instead, we find the rms of the residuals between the final fitting functions and the data to be dominated by errors in the stellar parameters. We provide fitting functions for both Lick/IDS and MILES spectral resolutions and compare our results with other fitting functions in the literature.
497. Compendium of ISO far-IR extragalactic data
ID:
ivo://CDS.VizieR/J/ApJS/178/280
Title:
Compendium of ISO far-IR extragalactic data
Short Name:
J/ApJS/178/280
Date:
21 Oct 2021
Publisher:
CDS
Description:
Far-infrared line and continuum fluxes are presented for a sample of 227 galaxies observed with the Long Wavelength Spectrometer on the Infrared Space Observatory (ISO, Kessler et al., 1996A&A...315L..27K). The galaxy sample includes normal star-forming systems, starbursts, and active galactic nuclei covering a wide range of colors and morphologies. The data set spans some 1300 line fluxes, 600 line upper limits, and 800 continuum fluxes. Several fine-structure emission lines are detected that arise in either photodissociation or HII regions: [OIII] 52um, [NIII] 57um, [OI] 63um, [OIII] 88um, [NII] 122um, [OI] 145um, and [CII] 158um. Molecular lines such as OH at 53, 79, 84, 119, and 163um, and H_2_O at 58, 66, 75, 101, and 108um are also detected in some galaxies. In addition to those lines emitted by the target galaxies, serendipitous detections of Milky Way [CII] 158um and an unidentified line near 74um in NGC 1068 are also reported. Finally, continuum fluxes at 52, 57, 63, 88, 122, 145, 158, and 170um are derived for a subset of galaxies in which the far-infrared emission is contained within the ~75" ISO LWS beam. The statistics of this large database of continuum and line fluxes, including trends in line ratios with the far-infrared color and infrared-to-optical ratio, are explored.
498. Completed KMOS^3D^ survey NIR obs.
ID:
ivo://CDS.VizieR/J/ApJ/886/124
Title:
Completed KMOS^3D^ survey NIR obs.
Short Name:
J/ApJ/886/124
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the completed KMOS^3D^ survey, an integral field spectroscopic survey of 739 log(M_*_/M_{sun}_)>9 galaxies at 0.6<z<2.7 using the K-band Multi Object Spectrograph (KMOS) at the Very Large Telescope. The KMOS3D survey provides a population-wide census of kinematics, star formation, outflows, and nebular gas conditions both on and off the star-forming galaxy main sequence through the spatially resolved and integrated properties of H{alpha}, [NII], and [SII] emission lines. We detect H{alpha} emission for 91% of galaxies on the main sequence of star formation and 79% overall. The depth of the survey has allowed us to detect galaxies with star formation rates below 1M_{sun}_/yr, as well as to resolve 81% of detected galaxies with >=3 resolution elements along the kinematic major axis. The detection fraction of H{alpha} is a strong function of both color and offset from the main sequence, with the detected and nondetected samples exhibiting different spectral energy distribution shapes. Comparison of H{alpha} and UV+IR star formation rates reveal that dust attenuation corrections may be underestimated by 0.5dex at the highest masses (log(M_*_/M_{sun}_)>10.5). We confirm our first year results of a high rotation-dominated fraction (monotonic velocity gradient and v_rot_/{sigma}_0_>3.36^0.5^) of 77% for the full KMOS^3D^ sample. The rotation-dominated fraction is a function of both stellar mass and redshift, with the strongest evolution measured over the redshift range of the survey for galaxies with log(M_*_/M_{sun}_)<10.5.
499. Complete spectrum of ethyl cyanide
ID:
ivo://CDS.VizieR/J/ApJ/714/476
Title:
Complete spectrum of ethyl cyanide
Short Name:
J/ApJ/714/476
Date:
21 Oct 2021
Publisher:
CDS
Description:
There is a general consensus that many of the unidentified features in astrophysical spectra are due to low lying excited vibrational and torsional states of a few molecules -commonly referred to as the astrophysical weeds. This is a challenging spectroscopic problem not only because there are many such states, but also because these states are often highly perturbed and difficult to analyze. We have previously described an alternative approach based on experimental, intensity-calibrated spectra taken at many temperatures. In this paper, we describe the procedures and results obtained with this approach for ethyl cyanide, strategies for archiving and disseminating these results, and the prospects for using these results to reduce the confusion limit in the powerful new observatories that are coming online.
500. Complete spectrum of methanol
ID:
ivo://CDS.VizieR/J/ApJ/782/75
Title:
Complete spectrum of methanol
Short Name:
J/ApJ/782/75
Date:
21 Oct 2021
Publisher:
CDS
Description:
The complete spectrum of methanol (CH_3_OH) has been characterized over a range of astrophysically significant temperatures in the 560.4-654.0GHz spectral region. Absolute intensity calibration and analysis of 166 experimental spectra recorded over a slow 248-398K temperature ramp provide a means for the simulation of the complete spectrum of methanol as a function of temperature. These results include contributions from v_t_=3 and other higher states that are difficult to model via quantum mechanical (QM) techniques. They also contain contributions from the ^13^C isotopologue in terrestrial abundance. In contrast to our earlier work on semi-rigid species, such as ethyl cyanide and vinyl cyanide, significant intensity differences between these experimental values and those calculated by QM methods were found for many of the lines. Analysis of these differences shows the difficulty of the calculation of dipole matrix elements in the context of the internal rotation of the methanol molecule. These results are used to both provide catalogs in the usual line frequency, linestrength, and lower state energy format, as well as in a frequency point-by-point catalog that is particularly well suited for the characterization of blended lines.

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