- ID:
- ivo://CDS.VizieR/III/83
- Title:
- IUE Low-Dispersion Reference Atlas I, Normal Stars
- Short Name:
- III/83
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The atlas contains the fluxes (2 angstroms/step) of 229 low-dispersion stellar spectra collected by the International Ultraviolet Explorer (IUE) satellite, compiled for the purpose of establishing reference spectral sequences in the ultraviolet range. The sequences have been constructed and the standard stars selected directly from the ultraviolet material, staying as far as possible within the general MK frame. The catalog is essentially composed of stars exhibiting normal behaviour in the ultraviolet. A few peculiar objects have, however, been included as an illustration of typical abnormalities. This work clearly pointed out the dangers of extrapolating a spectral classification based on a given wavelength range to another one, and, in particular, of using the MK spectral type alone outside its definition range.
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- ID:
- ivo://CDS.VizieR/J/ApJS/147/145
- Title:
- IUE low-dispersion spectra of white dwarfs
- Short Name:
- J/ApJS/147/145
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have produced an archive of the ultraviolet low-dispersion spectra for the full set of white dwarf stars observed with the International Ultraviolet Explorer (IUE) satellite over the course of its 18-yr mission. This archive contains the spectra of 322 individual degenerate stars which have been processed to optimize the signal-to- noise for each star. In particular, all spectra have been corrected for residual temporal and thermal effects and placed on the Hubble Space Telescope Faint Object Spectrograph absolute flux scale using procedures described by Massa & Fitzpatrick (2000ApJS..126..517M). Wherever possible, multiple observations of individual stars have been co-added to further enhance signal-to-noise and have been combined into a single spectrum including the full 1150 to 3150{AA} wavelength region observed by IUE. The contents of this spectral archive are described and the details of data reduction procedures are provided. The electronic files of the processed spectra are available, in FITS and ASCII formats, with the associated log file, at http://vega.lpl.arizona.edu/newsips/low/
- ID:
- ivo://CDS.VizieR/J/ApJS/119/83
- Title:
- IUE sample of binaries with hot component
- Short Name:
- J/ApJS/119/83
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained or retrieved IUE spectra for over 100 middle- and late-type giant and supergiant stars whose spectra indicate the presence of a hot component earlier than type F2. The hot companions are classified accurately by temperature class from their far-UV spectra. The interstellar extinction of each system and the relative luminosities of the components are derived from analysis of the UV and optical fluxes, using a grid of UV intrinsic colors for hot dwarfs. We find that there is fair agreement in general between current UV spectral classification and ground-based hot component types, in spite of the difficulties of assigning the latter. There are a few cases in which the cool component optical classifications disagree considerably with the temperature classes inferred from our analysis of UV and optical photometry. The extinction parameter agrees moderately well with other determinations of B-V color excess. Many systems are worthy of further study especially to establish their spectroscopic orbits. Further work is planned to estimate luminosities of the cool components from the data herein; in many cases, these luminosities' accuracies should be comparable to or exceed those of the Hipparcos parallaxes.
- ID:
- ivo://CDS.VizieR/J/A+A/331/633
- Title:
- IUE spectra of lambda Boo stars
- Short Name:
- J/A+A/331/633
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An analysis of the stars included in the catalogue of {lambda} Bootis stars by Paunzen et al. (1997, Cat. <J/A+AS/123/93>) and which also have IUE observations is presented here. Population I A-F type stars as well as field horizontal branch stars were also included in the analysis. Using line-ratios of carbon to heavier elements (Al and Ni) allows us to establish unambiguous membership criteria for the {lambda} Bootis group.
- ID:
- ivo://CDS.VizieR/J/ApJS/93/211
- Title:
- IUE survey of H I Ly{alpha} absorption. I.
- Short Name:
- J/ApJS/93/211
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We measure Galactic interstellar neutral hydrogen column densities by analyzing archival interstellar Ly{alpha} absorption line data toward 554 B2 and hotter stars observed at high resolution with the IUE satellite. This study more than doubles the number of lines of sight with measures of N(H I) based on Ly{alpha}. We have included the scattered light background correction algorithm of Bianchi and Bohlin (1984A&A...134...31B) in our data reduction. We use the correlation between the Balmer discontinuity [c_1_] index and the stellar Ly{alpha} absorption in order to assess the effects of stellar Ly alpha contamination. Approximately 40% of the B stars with measured [c_1_] index, exhibit serious stellar Ly{alpha} contamination. Table 1 contains the derived values of the interstellar N(H I) for 393 stars with at most small amounts of stellar contamination. Table 2 lists the observed values of total N(H I) for 161 stars with suspected stellar Ly alpha contamination and/or uncertain stellar parameters.
- ID:
- ivo://CDS.VizieR/J/AcA/54/347
- Title:
- IVB mag of LMC ellipsoidal variables
- Short Name:
- J/AcA/54/347
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We used the OGLE-II and OGLE-III photometry of red giants in the Large Magellanic Cloud to select and study objects revealing ellipsoidal variability. We detected 1546 candidates for long period ellipsoidal variables and 121 eclipsing binary systems with clear ellipsoidal modulation.
7267. IXPE Master Catalog
- ID:
- ivo://nasa.heasarc/ixmaster
- Title:
- IXPE Master Catalog
- Short Name:
- IXMASTER
- Date:
- 27 Sep 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- Launched in late 2021, the Imaging X-ray Polarimetry Explorer (IXPE) is a NASA Small Explorer Mission in collaboration with the Italian Space Agency (ASI). The mission measures X-ray polarization from compact objects such as neutron stars and black holes, which serve as laboratories for exploring extreme gravitational and magnetic fields. With its imaging capabilities, IXPE will also map the magnetic-field structure of a few extended sources such as supernova remnants and pulsar wind nebulae. This table contains a list of (a) unobserved targets that are planned for observation by IXPE in the future and (b) IXPE observations which have been processed and successfully validated by the IXPE team. The data from these observations may or may not be public and the user should check the value of the public_date parameter to determine the status of a specified data set. Only those ObsIDs which have a public_date in the past will have data publicly available. Observations with a public_date parameter value which is either blank or a date in the future have been ingested into the HEASARC archive but will remain encrypted until their public date. This contents of this database table are generated by the IXPE Team and updated regularly with new observations. These updates are then delivered to the HEASARC and ingested into the HEASARC database in a timely fashion. Note that some parameters have been added and are populated by the HEASARC. This is a service provided by NASA HEASARC .
- ID:
- ivo://CDS.VizieR/J/AJ/152/182
- Title:
- iz follow-up photometry of HAT-P-65 and HAT-P-66
- Short Name:
- J/AJ/152/182
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the discovery of the transiting exoplanets HAT-P-65b and HAT-P-66b, with orbital periods of 2.6055 and 2.9721 days, masses of 0.527+/-0.083M_J_ and 0.783+/-0.057M_J_, and inflated radii of 1.89+/-0.13R_J_ and 1.59_-0.10_^+0.16^R_J_, respectively. They orbit moderately bright (V=13.145+/-0.029 and V=12.993+/-0.052) stars of mass 1.212+/-0.050M_{Sun}_ and 1.255_-0.054_^+0.107^M_{Sun}_. The stars are at the main-sequence turnoff. While it is well known that the radii of close-in giant planets are correlated with their equilibrium temperatures, whether or not the radii of planets increase in time as their hosts evolve and become more luminous is an open question. Looking at the broader sample of well-characterized close-in transiting giant planets, we find that there is a statistically significant correlation between planetary radii and the fractional ages of their host stars, with a false-alarm probability of only 0.0041%. We find that the correlation between the radii of planets and the fractional ages of their hosts is fully explained by the known correlation between planetary radii and their present-day equilibrium temperatures; however, if the zero-age main-sequence equilibrium temperature is used in place of the present-day equilibrium temperature, then a correlation with age must also be included to explain the planetary radii. This suggests that, after contracting during the pre-main-sequence, close-in giant planets are reinflated over time due to the increasing level of irradiation received from their host stars. Prior theoretical work indicates that such a dynamic response to irradiation requires a significant fraction of the incident energy to be deposited deep within the planetary interiors.
- ID:
- ivo://CDS.VizieR/J/MNRAS/392/1034
- Title:
- IZJHKL' photometry of NGC 6611
- Short Name:
- J/MNRAS/392/1034
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- NGC 6611 is the massive young cluster (2-3Myr) that ionizes the Eagle Nebula. We present very deep photometric observations of the central region of NGC 6611 obtained with the Hubble Space Telescope and the following filters: ACS/WFC F775W and F850LP and NIC2 F110W and F160W, loosely equivalent to ground-based IZJH filters. This survey reaches down to I~26mag. We construct the initial mass function (IMF) from ~1.5M_{sun}_ well into the brown dwarf regime (down to ~0.02M_{sun}_). We have detected 30-35 brown dwarf candidates in this sample. The low-mass IMF is combined with a higher-mass IMF constructed from the ground-based catalogue from Oliveira et al. We compare the final IMF with those of well-studied star-forming regions: we find that the IMF of NGC 6611 more closely resembles that of the low-mass star-forming region in Taurus than that of the more massive Orion Nebula Cluster. We conclude that there seems to be no severe environmental effect in the IMF due to the proximity of the massive stars in NGC 6611.
- ID:
- ivo://CDS.VizieR/J/A+A/448/189
- Title:
- IzJHK photometry of IC4665
- Short Name:
- J/A+A/448/189
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a study of the young (30-100Myr) open cluster IC4665 with the aim to determine the shape of the mass function well into the brown dwarf regime. We photometrically select 691 low-mass and 94 brown dwarf candidate members over an area of 3.82 square degrees centred on the cluster. K-band follow-up photometry and Two-Micron All-Sky Survey (<II/246>) data allow a first filtering of contaminant objects from our catalogues. A second filtering is performed for the brightest stars using proper motion data provided by the Tycho-2 (<I/259>) and UCAC2 (<I/289>) public catalogues. Contamination by the field population for the lowest mass objects is estimated using same latitude control fields. We fit observed surface densities of various cluster populations with King profiles and find a consistent tidal radius of 1.0 degree. The presence of possible mass segregation is discussed. In most respects investigated, IC4665 is similar to other young open clusters of similar age: (1) an estimate of the mass function in the low-mass regime and crossing the hydrogen burning limit results in a power law description with slope -0.6, (2) a fraction of BD to total members between 10-19%, (3) a cusp in the mass function is seen at about the substellar boundary, (4) the best-fit lognormal function to the full mass distribution shows an average member mass of 0.32M_{sun}_ if IC4665 has an age of 50Myr.