Tables tablea1 to tablea6 show the absolute fluxes of the IUE standard stars used for the derivation of the cameras Inverse Sensitivity Curves for the IUE Final Archive. The relative fluxes of the standard stars have been derived with the WD model, and the zero point of the scale has been set by OAO-2 observations. These fluxes define the absolute flux scale of IUE. Table tableb1 contains the model fluxes of the White Dwarf G191 B2B scaled to the OAO-2 flux scale.
Ultimately all types in a VO-DML model are defined as hierarchies
of primitive types. This Model defines a special, predefined model
that contains a set of the most common of such types: integer,
real, string etc. This
This paper describes the first data release of the Kepler-INT Survey (KIS) that covers a 116deg^2^ region of the Cygnus and Lyra constellations. The Kepler field is the target of the most intensive search for transiting planets to date. Despite the fact that the Kepler mission provides superior time-series photometry, with an enormous impact on all areas of stellar variability, its field lacks optical photometry complete to the confusion limit of the Kepler instrument necessary for selecting various classes of targets. For this reason, we follow the observing strategy and data reduction method used in the IPHAS and UVEX galactic plane surveys in order to produce a deep optical survey of the Kepler field. This initial release concerns data taken between 2011 May and August, using the Isaac Newton Telescope on the island of La Palma. Four broadband filters were used, U, g, r, i, as well as one narrowband one, H{alpha}, reaching down to a 10{sigma} limit of ~20th mag in the Vega system. Observations covering ~5 deg^2^, thus about half of the field, passed our quality control thresholds and constitute this first data release. We derive a global photometric calibration by placing the KIS magnitudes as close as possible to the Kepler Input Catalog (KIC) photometry. The initial data release catalog containing around 6 million sources from all the good photometric fields is available for download from the KIS Web site (www.astro.warwick.ac.uk/research/kis/) as well as via MAST (KIS magnitudes can be retrieved using the MAST enhanced target search page http://archive.stsci.edu/kepler/kepler_fov/search.php and also via Casjobs at MAST Web site http://mastweb.stsci.edu/kplrcasjobs/).
We present the discovery of the Kepler-20 planetary system, which we initially identified through the detection of five distinct periodic transit signals in the Kepler light curve of the host star 2MASS J19104752+4220194. From high-resolution spectroscopy of the star, we find a stellar effective temperature T_eff_= 5455+/-100 K, a metallicity of [Fe/H] = 0.01+/-0.04, and a surface gravity of log g = 4.4+/-0.1. We combine these estimates with an estimate of the stellar density derived from the transit light curves to deduce a stellar mass of M_*_ = 0.912+/-0.034 M_{sun}_and a stellar radius of R_*_ = 0.944^+0.060^_-0.095_R_{sun}_. For three of the transit signals, we demonstrate that our results strongly disfavor the possibility that these result from astrophysical false positives. We determine the orbital periods and physical radii of the three confirmed planets to be 3.70 days and 1.91^+0.12^_-0.21_R_{earth}_ for Kepler-20b, 10.85 days and 3.07^+0.20^_-0.31_R_{earth}_ for Kepler-20c, and 77.61 days and 2.75^+0.17^_-0.30_R_{earth}_ for Kepler-20d. From multi-epoch radial velocities, we determine the masses of Kepler-20b and Kepler-20c to be 8.7+/-2.2 M_{earth}_ and 16.1 +/-3.5 M_{earth}_, respectively, and we place an upper limit on the mass of Kepler-20d of 20.1 M_{earth}_(2{sigma}).
Variability-induced motion (VIM) is an observable effect in simultaneous astrometric and photometric measurements caused by brightness variation in one of the components of a double source or blended image, which manifests itself as a strongly correlated shift of the optical photocenter. We have processed the entire collection of Kepler long-cadence light curve data, looking for correlated signals in astrometry and photometry on the time basis of a quarter-year. Limiting the VIM correlation coefficient to 0.3, VIM events are detected for 129525 Kepler stars in at least one quarter. Of 7305 Kepler objects of interest, 4440 are detected as VIM at least once. Known variable stars and resolved double stars have elevated rates of VIM detection. Confident VIM occurrences are found for stars with suggested superflare events, indicating possible signal contamination. We present a complete catalog of all quarterly VIM detections. This catalog should be checked for such astrophysically significant events as transits of exoplanets, new eclipsing stars, and superflares of solar-type stars.
The kinematics of the C II {lambda}6578 line in PNe
Short Name:
J/AJ/153/140
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present spectroscopic observations of the C II {lambda}6578 permitted line for 83 lines of sight in 76 planetary nebulae at high spectral resolution, most of them obtained with the Manchester Echelle Spectrograph on the 2.1 m telescope at the Observatorio Astronomico Nacional on the Sierra San Pedro Martir. We study the kinematics of the C II {lambda}6578 permitted line with respect to other permitted and collisionally excited lines. Statistically, we find that the kinematics of the C II {lambda}6578 line are not those expected if this line arises from the recombination of C^2+^ ions or the fluorescence of C^+^ ions in ionization equilibrium in a chemically homogeneous nebular plasma, but instead its kinematics are those appropriate for a volume more internal than expected. The planetary nebulae in this sample have well-defined morphology and are restricted to a limited range in H{alpha} line widths (no large values) compared to their counterparts in the Milky Way bulge; both these features could be interpreted as the result of young nebular shells, an inference that is also supported by nebular modeling. Concerning the long-standing discrepancy between chemical abundances inferred from permitted and collisionally excited emission lines in photoionized nebulae, our results imply that multiple plasma components occur commonly in planetary nebulae.
We present Korea Microlensing Telescope Network (KMTNet) light curves for microlensing-event candidates in the Kepler K2 C9 field having peaks within three effective timescales of the Kepler observations. These include 181 "clear microlensing" and 84 "possible microlensing" events found by the KMTNet event finder, plus 56 other events found by OGLE and/or MOA that were not found by KMTNet. All data for the first two classes are immediately available for public use without restriction.
The second catalog of active galactic nuclei (AGNs) detected by the Fermi Large Area Telescope (LAT) in two years of scientific operation is presented. The second LAT AGN catalog (2LAC) includes 1017 {gamma}-ray sources located at high Galactic latitudes (|b|>10{deg}) that are detected with a test statistic (TS) greater than 25 and associated statistically with AGNs. However, some of these are affected by analysis issues and some are associated with multiple AGNs. Consequently, we define a Clean Sample which includes 886 AGNs, comprising 395 BL Lacertae objects (BL Lac objects), 310 flat-spectrum radio quasars (FSRQs), 157 candidate blazars of unknown type (i.e., with broadband blazar characteristics but with no optical spectral measurement yet), 8 misaligned AGNs, 4 narrow-line Seyfert 1 (NLS1s), 10 AGNs of other types, and 2 starburst galaxies. Where possible, the blazars have been further classified based on their spectral energy distributions (SEDs) as archival radio, optical, and X-ray data permit. While almost all FSRQs have a synchrotron-peak frequency <10^14^Hz, about half of the BL Lac objects have a synchrotron-peak frequency >10^15^Hz. The 2LAC represents a significant improvement relative to the first LAT AGN catalog (1LAC), with 52% more associated sources. The full characterization of the newly detected sources will require more broadband data. Various properties, such as {gamma}-ray fluxes and photon power-law spectral indices, redshifts, {gamma}-ray luminosities, variability, and archival radio luminosities and their correlations are presented and discussed for the different blazar classes. The general trends observed in 1LAC are confirmed.
The table shows clump parameters for 130 peaks in CO(J=1->0) emission detected in the Lambda-Orionis ring in the survey of Lang et al. (1998PASA...15...70L). The clumps were isolated using the Clumpfind algorithm of Williams et al. (1994, Cat. <J/ApJ/428/693>). They are ordered and labelled according to the relative brightness of the peak temperatures within them, so clump 1 contains the emission maximum, but not necessarily the maximum W(CO) or largest mass.