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3191. Companions to APOGEE stars. I.
ID:
ivo://CDS.VizieR/J/AJ/151/85
Title:
Companions to APOGEE stars. I.
Short Name:
J/AJ/151/85
Date:
21 Oct 2021
Publisher:
CDS
Description:
In its three years of operation, the Sloan Digital Sky Survey Apache Point Observatory Galactic Evolution Experiment (APOGEE-1) observed >14000 stars with enough epochs over a sufficient temporal baseline for the fitting of Keplerian orbits. We present the custom orbit-fitting pipeline used to create this catalog, which includes novel quality metrics that account for the phase and velocity coverage of a fitted Keplerian orbit. With a typical radial velocity precision of ~100-200 m/s, APOGEE can probe systems with small separation companions down to a few Jupiter masses. Here we present initial results from a catalog of 382 of the most compelling stellar and substellar companion candidates detected by APOGEE, which orbit a variety of host stars in diverse Galactic environments. Of these, 376 have no previously known small separation companion. The distribution of companion candidates in this catalog shows evidence for an extremely truncated brown dwarf (BD) desert with a paucity of BD companions only for systems with a<0.1-0.2 AU, with no indication of a desert at larger orbital separation. We propose a few potential explanations of this result, some which invoke this catalog's many small separation companion candidates found orbiting evolved stars. Furthermore, 16 BD and planet candidates have been identified around metal-poor ([Fe/H]<-0.5) stars in this catalog, which may challenge the core accretion model for companions >10 M_Jup_. Finally, we find all types of companions are ubiquitous throughout the Galactic disk with candidate planetary-mass and BD companions to distances of ~6 and ~16 kpc, respectively.
3192. Companions to close spectroscopic binaries
ID:
ivo://CDS.VizieR/J/A+A/450/681
Title:
Companions to close spectroscopic binaries
Short Name:
J/A+A/450/681
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have surveyed a sample of 165 solar-type spectroscopic binaries (SB) with periods from 1 to 30 days for higher-order multiplicity. 62 targets have been observed with the NACO adaptive optics system and 13 new physical tertiary companions were detected. Another 12 new wide companions (5 still tentative) were retrieved from the 2MASS (<II/246>) sky survey. Our binaries belong to 161 stellar systems; of these 64 are triple, 11 quadruple and 7 quintuple. After correction for incomplete detection, the fraction of SBs with additional companions is 63+/-5%. We find that this fraction is a strong function of the SB period P, reaching 96% for P<3d and dropping to 36% for P>12d. Period distributions of SBs with and without tertiaries are significantly different, but their mass ratio distributions are identical. New statistical data on the multiplicity of close SBs indicate that their periods and mass ratios were established very early, but periods of SBs within triples were further shortened by angular momentum exchange with companions.
3193. Companions to isolated elliptical galaxies
ID:
ivo://CDS.VizieR/J/ApJ/607/810
Title:
Companions to isolated elliptical galaxies
Short Name:
J/ApJ/607/810
Date:
21 Oct 2021
Publisher:
CDS
Description:
We investigate the number of physical companion galaxies for a sample of relatively isolated elliptical galaxies. The NASA/IPAC Extragalactic Database (NED) has been used to reinvestigate the incidence of satellite galaxies for a sample of 34 elliptical galaxies, first investigated by Bothun & Sullivan (1977PASP...89....5B) using a visual inspection of Palomar Sky Survey prints out to a projected search radius of 75 kpc. We have repeated their original investigation using data cataloged in NED. Nine of these elliptical galaxies appear to be members of galaxy clusters; the remaining sample of 25 galaxies reveals an average of +1.0+/-0.5 apparent companions per galaxy within a projected search radius of 75 kpc, in excess of two equal-area comparison regions displaced by 150-300 kpc. This is significantly larger than the +0.12+/-0.42 companions/galaxy found by Bothun & Sullivan (1977PASP...89....5B) for the identical sample. Making use of published radial velocities, mostly available since the completion of the Bothun-Sullivan study, identifies the physical companions and gives a somewhat lower estimate of +0.4 companions per elliptical galaxy. This is still 3 times larger than the original statistical study, but given the incomplete and heterogeneous nature of the survey redshifts in NED, it still yields a firm lower limit on the number (and identity) of physical companions. An expansion of the search radius out to 300 kpc, again restricted to sampling only those objects with known redshifts in NED, gives another lower limit of 4.5 physical companions per galaxy. (Excluding five elliptical galaxies in the Fornax Cluster, this average drops to 3.5 companions per elliptical.) These physical companions are individually identified and listed, and the ensemble-averaged radial density distribution of these associated galaxies is presented. For the ensemble, the radial density distribution is found to have a falloff consistent with {rho}{prop.to}R^-0.5^ out to approximately 150 kpc. For non-Fornax Cluster companions the falloff continues out to the 300 kpc limit of the survey. The velocity dispersion of these companions is found to reach a maximum of 350 km/s at around 120 kpc, after which they fall at a rate consistent with Keplerian falloff. This falloff may then indicate the detection of a cut-off in the mass-density distribution in the elliptical galaxies' dark matter halo at ~100 kpc.
3194. Companions to M dwarfs within 5pc
ID:
ivo://CDS.VizieR/J/A+A/325/159
Title:
Companions to M dwarfs within 5pc
Short Name:
J/A+A/325/159
Date:
21 Oct 2021
Publisher:
CDS
Description:
The paper contains four tables which summarise the duplicity status of the 34 M dwarf primaries within 5.0pc. Table 1 gives the basic data for the sample: designation, coordinates, V,J,H,K photometry, parallax Table 2 gives, for the nine southern sources, magnitude limits for possible undetected companions. These limits are given for assumed projected separations of 1AU, 2AU, 5AU, and 10AU. In addition, the circumstances of the observation are given: date, telescope, and observational technique. Table 3 repeats, in updated form, the same information (except for the date) for the 25 northern sources. Table 4 lists the nine M dwarf primaries within 5pc which do have one or more companions.
3195. 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.
3196. Comparative habitability of transiting exoplanets
ID:
ivo://CDS.VizieR/J/ApJ/814/91
Title:
Comparative habitability of transiting exoplanets
Short Name:
J/ApJ/814/91
Date:
21 Oct 2021
Publisher:
CDS
Description:
Exoplanet habitability is traditionally assessed by comparing a planet's semimajor axis to the location of its host star's "habitable zone", the shell around a star for which Earth-like planets can possess liquid surface water. The Kepler space telescope has discovered numerous planet candidates near the habitable zone, and many more are expected from missions such as K2, TESS, and PLATO. These candidates often require significant follow-up observations for validation, so prioritizing planets for habitability from transit data has become an important aspect of the search for life in the universe. We propose a method to compare transiting planets for their potential to support life based on transit data, stellar properties and previously reported limits on planetary emitted flux. For a planet in radiative equilibrium, the emitted flux increases with eccentricity, but decreases with albedo. As these parameters are often unconstrained, there is an "eccentricity-albedo degeneracy" for the habitability of transiting exoplanets. Our method mitigates this degeneracy, includes a penalty for large-radius planets, uses terrestrial mass-radius relationships, and, when available, constraints on eccentricity to compute a number we call the "habitability index for transiting exoplanets" that represents the relative probability that an exoplanet could support liquid surface water. We calculate it for Kepler objects of interest and find that planets that receive between 60% and 90% of the Earth's incident radiation, assuming circular orbits, are most likely to be habitable. Finally, we make predictions for the upcoming TESS and James Webb Space Telescope missions.
3197. Compared rotation periods for 1189 CKS host stars
ID:
ivo://CDS.VizieR/J/AJ/161/265
Title:
Compared rotation periods for 1189 CKS host stars
Short Name:
J/AJ/161/265
Date:
16 Mar 2022 11:58:11
Publisher:
CDS
Description:
The radius valley, a bifurcation in the size distribution of small, close-in exoplanets, is hypothesized to be a signature of planetary atmospheric loss. Such an evolutionary phenomenon should depend on the age of the star-planet system. In this work, we study the temporal evolution of the radius valley using two independent determinations of host star ages among the California-Kepler Survey (CKS) sample. We find evidence for a wide and nearly empty void of planets in the period-radius diagram at the youngest system ages (<~2-3Gyr) represented in the CKS sample. We show that the orbital period dependence of the radius valley among the younger CKS planets is consistent with that found among those planets with asteroseismically determined host star radii. Relative to previous studies of preferentially older planets, the radius valley determined among the younger planetary sample is shifted to smaller radii. This result is compatible with an atmospheric loss timescale on the order of gigayears for progenitors of the largest observed super-Earths. In support of this interpretation, we show that the planet sizes that appear to be unrepresented at ages <~2-3Gyr are likely to correspond to planets with rocky compositions. Our results suggest that the size distribution of close-in exoplanets and the precise location of the radius valley evolve over gigayears.
3198. 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.
3199. Comparison of Radio-loud and Quiet Quasars
ID:
ivo://CDS.VizieR/J/ApJ/511/612
Title:
Comparison of Radio-loud and Quiet Quasars
Short Name:
J/ApJ/511/612
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have made radio observations of 87 optically selected quasars at 5 GHz with the VLA in order to measure the radio power for these objects and hence determine how the fraction of radio-loud quasars varies with redshift and optical luminosity. The sample has been selected from the recently completed Edinburgh Quasar Survey and covers a redshift range of 0.3{<=}z{<=}1.5 and an optical absolute magnitude range of (-26.5){<=}M_B_{<=}(-23.5) (h=1/2, q_o_=1/2). We have also matched other existing surveys with the Faint Images of the Radio Sky at Twenty Centimeters and NRAO VLA Sky Survey radio catalogs and combined these data so that the optical luminosity-redshift plane is now far better sampled than before. We have fitted a model to the probability of a quasar being radio-loud as a function of absolute magnitude and redshift, and from this model we infer the radio-loud and radio-quiet optical luminosity functions. The radio-loud optical luminosity function is featureless and flatter than the radio-quiet one. It evolves at a marginally slower rate if quasars evolve by density evolution, but the difference in the rate of evolutions of the two different classes is much less than was previously thought.
3200. 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.

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