- ID:
- ivo://CDS.VizieR/J/ApJS/233/3
- Title:
- The VLBA Extragalactic Proper Motion Catalog
- Short Name:
- J/ApJS/233/3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of extragalactic proper motions created using archival VLBI data and our own VLBA astrometry. The catalog contains 713 proper motions, with average uncertainties of ~24{mu}as/yr, including 40 new or improved proper motion measurements using relative astrometry with the VLBA. The observations were conducted in the X-band and yielded positions with uncertainties of ~70{mu}as. We add 10 new redshifts using spectroscopic observations taken at Apache Point Observatory and Gemini North. With the VLBA Extragalactic Proper Motion Catalog, we detect the secular aberration drift-the apparent motion of extragalactic objects caused by the solar system's acceleration around the Galactic center-at a 6.3{sigma} significance. We model the aberration drift as a spheroidal dipole, with the square root of the power equal to 4.89+/-0.77{mu}as/yr, an amplitude of 1.69+/-0.27{mu}as/yr, and an apex at (275.2{deg}+/-10.0{deg}, -29.4{deg}+/-8.8{deg}). Our dipole model detects the aberration drift at a higher significance than some previous studies, but at a lower amplitude than expected or previously measured. The full aberration drift may be partially removed by the no-net-rotation constraint used when measuring archival extragalactic radio source positions. Like the cosmic microwave background dipole, which is induced by the observer's motion, the aberration drift signal should be subtracted from extragalactic proper motions in order to detect cosmological proper motions, including the Hubble expansion, long-period stochastic gravitational waves, and the collapse of large-scale structure.
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- ID:
- ivo://CDS.VizieR/J/ApJ/708/1076
- Title:
- The WHIQII survey: compact blue galaxies
- Short Name:
- J/ApJ/708/1076
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- As part of the WIYN High Image Quality Indiana-Irvine (WHIQII) survey, we present 123 spectra of faint emission-line galaxies, selected to focus on intermediate redshift (0.4<~z<~0.8) galaxies with blue colors that appear physically compact on the sky. The sample includes 15 true Luminous Compact Blue Galaxies (LCBGs) and an additional 27 slightly less extreme emission-line systems. These galaxies represent a highly evolving class that may play an important role in the decline of star formation since z~1, but their exact nature and evolutionary pathways remain a mystery. Here, we use emission lines to determine metallicities and ionization parameters, constraining their intrinsic properties and state of star formation. Some LCBG metallicities are consistent with a "bursting dwarf" scenario, while a substantial fraction of others are not, further confirming that LCBGs are a highly heterogeneous population but are broadly consistent with the intermediate redshift field. In agreement with previous studies, we observe overall evolution in the luminosity-metallicity relation at intermediate redshift. Our sample, and particularly the LCBGs, occupies a region in the empirical R_23_-O_32_ plane that differs from luminous local galaxies and is more consistent with dwarf irregulars at the present epoch, suggesting that cosmic "downsizing" is observable in even the most fundamental parameters that describe star formation.
- ID:
- ivo://CDS.VizieR/J/A+A/468/1115
- Title:
- Thorium and argon lines in the visible
- Short Name:
- J/A+A/468/1115
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new list of thorium and argon emission lines in the visible obtained by analyzing high-resolution (R=110000) spectra of a ThAr hollow cathode lamp. The aim of this new line list is to allow significant improvements in the quality of wavelength calibration for medium- to high-resolution astronomical spectrographs. We use a series of ThAr lamp exposures obtained with the HARPS instrument (High Accuracy Radial-velocity Planet Searcher) to detect previously unknown lines, perform a systematic search for blended lines and correct individual wavelengths by determining the systematic offset of each line relative to the average wavelength solution.
- ID:
- ivo://CDS.VizieR/J/ApJS/211/4
- Title:
- Thorium spectrum from 250nm to 5500nm
- Short Name:
- J/ApJS/211/4
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have made precise observations of a thorium-argon hollow cathode lamp emission spectrum in the region between 350nm and 1175nm using a high-resolution Fourier transform spectrometer. Our measurements are combined with results from seven previously published thorium line lists to re-optimize the energy levels of neutral, singly, and doubly ionized thorium (Th I, Th II, and Th III). Using the optimized level values, we calculate accurate Ritz wavelengths for 19874 thorium lines between 250nm and 5500nm (40000/cm to 1800/cm). We have also found 102 new thorium energy levels. A systematic analysis of previous measurements in light of our new results allows us to identify and propose corrections for systematic errors in Palmer & Engleman (1983ats..book.....P) and typographical errors and incorrect classifications in Kerber et al. (2008ApJS..178..374K). We also found a large scatter with respect to the thorium line list of Lovis & Pepe (Cat. J/A+A/468/1115). We anticipate that our Ritz wavelengths will lead to improved measurement accuracy for current and future spectrographs that make use of thorium-argon or thorium-neon lamps as calibration standards.
- ID:
- ivo://CDS.VizieR/J/ApJS/230/16
- Title:
- 05 through L3 empirical stellar spectra from SDSS
- Short Name:
- J/ApJS/230/16
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a library of empirical stellar spectra created using spectra from the Sloan Digital Sky Survey's Baryon Oscillation Spectroscopic Survey. The templates cover spectral types O5 through L3, are binned by metallicity from -2.0dex through +1.0dex, and are separated into main-sequence (dwarf) stars and giant stars. With recently developed M dwarf metallicity indicators, we are able to extend the metallicity bins down through the spectral subtype M8, making this the first empirical library with this degree of temperature and metallicity coverage. The wavelength coverage for the templates is from 3650 to 10200{AA} at a resolution of better than R~2000. Using the templates, we identify trends in color space with metallicity and surface gravity, which will be useful for analyzing large data sets from upcoming missions like the Large Synoptic Survey Telescope. Along with the templates, we are releasing a code for automatically (and/or visually) identifying the spectral type and metallicity of a star.
- ID:
- ivo://CDS.VizieR/J/MNRAS/404/1321
- Title:
- TiII in Milky way and Magellanic clouds
- Short Name:
- J/MNRAS/404/1321
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We discuss several sets of TiII absorption-line data, which probe a variety of interstellar environments in our Galaxy and in the Magellanic Clouds. Comparisons of high-resolution [full width at half-maximum (FWHM)~1.3-1.5km/s] TiII spectra of Galactic targets with corresponding high-resolution spectra of NaI, KI and CaII reveal both similarities and differences in the detailed structure of the absorption-line profiles - reflecting component-to-component differences in the ionization and depletion behaviour of those species. Moderate-resolution (FWHM~3.4-4.5km/s) spectra of more heavily reddened Galactic stars provide more extensive information on the titanium depletion in colder, denser clouds - where more than 99.9 per cent of the Ti may be in the dust phase. Moderate-resolution (FWHM~4.5-8.7km/s) spectra of stars in the Magellanic Clouds suggest that the titanium depletion is generally much less severe in the Large and Small Magellanic Clouds than in our Galaxy [for a given N(Htot), E(B-V), or molecular fraction f(H2)]- providing additional evidence for differences in depletion patterns in those two lower-metallicity galaxies. We briefly discuss possible implications of these results for the interpretation of gas-phase abundances in quasi-stellar object absorption-line systems and of variations in the D/H ratio in the local Galactic interstellar medium.
- ID:
- ivo://CDS.VizieR/J/AJ/146/97
- Title:
- Ti line list for the Lick hallow-cathode lamp
- Short Name:
- J/AJ/146/97
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the wavelength calibration of the Hamilton echelle spectrograph (the Lick observatory). The main problem of the calibration arises from the fact that thorium lines are absent in the spectrum of ThAr hollow-cathode lamp now under the operation. On the other hand, numerous unknown strong lines are present in the spectrum. These lines was identified with titanium. We estimate the temperature of the lamp gas which permits us to calculate the intensities of the lines, and to select a large number of relevant TiI and TiII lines. The titanium line list for the Lick hallow-cathode lamp is presented. The wavelength calibration using this line list was made with accuracy about 0.006{AA}.
- ID:
- ivo://CDS.VizieR/J/AJ/127/3121
- Title:
- TKRS catalog of GOODS-North Field
- Short Name:
- J/AJ/127/3121
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the results of an extensive imaging and spectroscopic survey in the Great Observatories Origins Deep Survey (GOODS)-North field completed using DEIMOS on the Keck II telescope. Observations of 2018 targets in a magnitude-limited sample of 2911 objects to R_AB_=24.4 yield secure redshifts for a sample of 1440 galaxies and active galactic nuclei (AGNs) plus 96 stars. In addition to redshifts and associated quality assessments, our catalog also includes photometric and astrometric measurements for all targets detected in our R-band imaging survey of the GOODS-North region.
- ID:
- ivo://CDS.VizieR/J/A+A/507/1649
- Title:
- Tohoku-Hiroshima-Nagoya planetary spectra library
- Short Name:
- J/A+A/507/1649
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A comprehensive framework for comparing spectral data from different planets has yet to be established. This framework is needed for the study of extrasolar planets and objects within the solar system. We completed observations to compile a library of planet spectra for all planets, some moons, and some dwarf planets in the solar system to study their general spectroscopic and photometric natures. During May and November of 2008, we acquired spectra for the planets using TRISPEC, which is capable of simultaneous three-band spectroscopy across a wide wavelength range of 0.45-2.5um with low resolving power ({lambda}{Delta}{lambda}~140-360).
- ID:
- ivo://CDS.VizieR/J/AJ/153/258
- Title:
- 2007.5 to 2010.4 HST astrometry of HD 202206
- Short Name:
- J/AJ/153/258
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using Hubble Space Telescope Fine Guidance Sensor astrometry and previously published radial velocity measures, we explore the exoplanetary system HD202206. Our modeling results in a parallax, {pi}_abs_=21.96+/-0.12 milliseconds of arc, a mass for HD202206B of M_B_=0.089_-0.006_^+0.007M_{Sun}_, and a mass for HD202206c of M_c_=17.9_-1.8_^+2.9^M_Jup_. HD202206 is a nearly face-on G + M binary orbited by a brown dwarf. The system architecture that we determine supports past assertions that stability requires a 5:1 mean motion resonance (we find a period ratio, P_c_/P_B_=4.92+/-0.04) and coplanarity (we find a mutual inclination, {Phi}=6{deg}+/-2{deg}).
