- ID:
- ivo://CDS.VizieR/J/A+A/623/A21
- Title:
- Thermal dust modified black-body parameter maps
- Short Name:
- J/A+A/623/A21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Planck data releases have provided the community with submillimetre and full-sky radio observations at unprecedented resolutions. We make use of the Planck 353, 545, and 857GHz maps alongside the IRAS 3000 GHz map. These maps contain information on the cosmic microwave background (CMB), cosmic infrared background (CIB), extragalactic point sources, and diffuse thermal dust emission. We aim to determine the modified black-body (MBB) model parameters of thermal dust emission in total intensity and produce all-sky maps of pure thermal dust, having separated this Galactic component from the CMB and CIB. This separation is completed using a new, sparsity-based, parametric method, Parameter Recovery Exploiting Model Informed Sparse Estimates (premise). The method is comprised of three main stages: 1) filtering the raw data to reduce the effect of the CIB on the MBB fit; 2) fitting an MBB model to the filtered data across super-pixels of various sizes determined by the algorithm itself; and 3) refining these super-pixel estimates into full-resolution maps of the MBB parameters. We present our maps of MBB temperature, spectral index, and optical depth at 5-arcmin resolution and compare our estimates to those of GNILC and to the two-step MBB fit presented by the Planck collaboration in 2013. By exploiting sparsity we avoid the need for smoothing, enabling us to produce the first full-resolution MBB parameter maps from intensity measurements of thermal dust emission.We consider the premise parameter estimates to be competitive with the existing state-of-the-art solutions, outperforming these methods within low signal-to-noise regions as we account for the CIB without removing thermal dust emission through oversmoothing.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/386/1001
- Title:
- Thermal emission from low-field neutron stars
- Short Name:
- J/A+A/386/1001
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new grid of LTE model atmospheres for weakly magnetic (B<~10^10^G) neutron stars, using X opacity and equation of state data from the OPAL project and employing a fully frequency- and angle-dependent radiation transfer. Model spectra for low-field neutron stars with three different photospheric compositions are presented: (1) pure hydrogen atmospheres, (2) atmospheres with solar abundances, and (3) pure iron atmospheres. Each grid covers 29 effective temperatures log(Teff[K])=5.10-6.50 in steps of 0.05. The model spectra are tabulated as angle-averaged unredshifted (surface) Eddington fluxes. All spectra have been calculated for a canonical neutron star configuration, M_ns_=1.4M_{sun}_, R_ns_=10km, corresponding to a surface gravitational acceleration of log(g)=14.386. The same model grids are also available as XSPEC tables at http://legacy.gsfc.nasa.gov/docs/xanadu/xspec/models/gbr.html
- ID:
- ivo://CDS.VizieR/J/A+A/640/L5
- Title:
- Thermal emission spectrum of WASP-189b
- Short Name:
- J/A+A/640/L5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Temperature inversion layers are predicted to be present in ultra-hot giant planet atmospheres. Although such inversion layers have recently been observed in several ultra-hot Jupiters, the chemical species responsible for creating the inversion remain unidentified. Here, we present observations of the thermal emission spectrum of an ultra-hot Jupiter, WASP-189b, at high spectral resolution using the HARPS-N spectrograph. Using the cross-correlation technique, we detect a strong FeI signal. The detected FeI spectral lines are found in emission, which is direct evidence of a temperature inversion in the planetary atmosphere. We further performed a retrieval on the observed spectrum using a forward model with an MCMC approach. When assuming a solar metallicity, the best-fit result returns a temperature of 4320 K at the top of the inversion, which is significantly hotter than the planetary equilibrium temperature (2641 K). The temperature at the bottom of the inversion is determined as 2200 K. Such a strong temperature inversion is probably created by the absorption of atomic species like FeI.
- ID:
- ivo://CDS.VizieR/J/AZh/71/37
- Title:
- Thermal Methanol from 33 Clouds at 48 GHz
- Short Name:
- J/AZh/71/37
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A search for thermal emission in the 1_0_-0_0_A^+^ methanol line was made at a frequency of 48.4GHz toward many celestial molecular clouds. The line was found in 33 clouds, and the methanol abundance varied over a large interval from 10^-9^ to 10^-7^.
- ID:
- ivo://CDS.VizieR/J/AJ/156/60
- Title:
- Thermal model fits for short-arc NEOs with NEOWISE
- Short Name:
- J/AJ/156/60
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Automated asteroid detection routines set requirements on the number of detections, signal-to-noise ratio, and the linearity of the expected motion in order to balance completeness, reliability, and time delay after data acquisition when identifying moving object tracklets. However, when the full-frame data from a survey are archived, they can be searched later for asteroids that were below the initial detection thresholds. We have conducted such a search of the first three years of the reactivated Near-Earth Object Wide-field Infrared Survey Explorer data, looking for near-Earth objects discovered by ground-based surveys that have previously unreported thermal infrared data. Using these measurements, we can then perform thermal modeling to measure the diameters and albedos of these objects. We present new physical properties for 116 Near-Earth Objects found in this search.
- ID:
- ivo://CDS.VizieR/J/A+A/625/A139
- Title:
- Thermal properties of slow asteroids
- Short Name:
- J/A+A/625/A139
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Earlier work suggests that slowly rotating asteroids should have higher thermal inertias than faster rotators because the heat wave penetrates deeper into the subsurface. However, thermal inertias have been determined mainly for fast rotators due to selection effects in the available photometry used to obtain shape models required for thermophysical modelling (TPM). Our aims are to mitigate these selection effects by producing shape models of slow rotators, to scale them and compute their thermal inertia with TPM, and to verify whether thermal inertia increases with the rotation period. To decrease the bias against slow rotators, we conducted a photometric observing campaign of main-belt asteroids with periods longer than 12h, from multiple stations worldwide, adding in some cases data from WISE and Kepler space telescopes. For spin and shape reconstruction we used the lightcurve inversion method, and to derive thermal inertias we applied a thermophysical model to fit available infrared data from IRAS, AKARI, and WISE. We present new models of 11 slow rotators that provide a good fit to the thermal data. In two cases, the TPM analysis showed a clear preference for one of the two possible mirror solutions. We derived the diameters and albedos of our targets in addition to their thermal inertias, which ranged between 3_-3_^+33^ and 45_-30_^+60^J/m^2^/s^1/2^/K. Together with our previous work, we have analysed 16 slow rotators from our dense survey with sizes between 30 and 150 km. The current sample thermal inertias vary widely, which does not confirm the earlier suggestion that slower rotators have higher thermal inertias.
- ID:
- ivo://CDS.VizieR/J/A+A/595/A130
- Title:
- Thermodynamic quantities of molecular hydrogen
- Short Name:
- J/A+A/595/A130
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Hydrogen is the most abundant molecule in the Universe. Its thermodynamic quantities dominate the physical conditions in molecular clouds, protoplanetary disks, etc. It is also of high interest in plasma physics. Therefore thermodynamic data for molecular hydrogen have to be as accurate as possible in a wide temperature range. We here rigorously show the shortcomings of various simplifications that are used to calculate the total internal partition function. These shortcomings can lead to errors of up to 40 percent or more in the estimated partition function. These errors carry on to calculations of thermodynamic quantities. Therefore a more complicated approach has to be taken. Seven possible simplifications of various complexity are described, together with advantages and disadvantages of direct summation of experimental values. These were compared to what we consider the most accurate and most complete treatment (case 8). Dunham coefficients were determined from experimental and theoretical energy levels of a number of electronically excited states of H2. Both equilibrium and normal hydrogen was taken into consideration.
- ID:
- ivo://CDS.VizieR/J/ApJS/245/19
- Title:
- Thermonuclear burst oscillations (TBOs) with RXTE
- Short Name:
- J/ApJS/245/19
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe a blind uniform search for thermonuclear burst oscillations (TBOs) in the majority of Type I bursts observed by the Rossi X-ray Timing Explorer (RXTE) (2118 bursts from 57 neutron stars). We examined 2-2002Hz power spectra from the Fourier transform in sliding 0.5-2s windows, using fine-binned light curves in the 2-60keV energy range. The significance of the oscillation candidates was assessed by simulations which took into account light-curve variations, dead time, and the sliding time windows. Some of our sources exhibited multi-frequency variability at <~15Hz that cannot be readily removed with light-curve modeling and may have an astrophysical (non-TBO) nature. Overall, we found that the number and strength of potential candidates depends strongly on the parameters of the search. We found candidates from all previously known RXTE TBO sources, with pulsations that had been detected at similar frequencies in multiple independent time windows, and discovered TBOs from SAXJ1810.8-2658. We could not confirm most previously reported tentative TBO detections or identify any obvious candidates just below the detection threshold at similar frequencies in multiple bursts. We computed fractional amplitudes of all TBO candidates and placed upper limits on non-detections. Finally, for a few sources we noted a small excess of candidates with powers comparable to fainter TBOs, but appearing in single independent time windows at random frequencies. At least some of these candidates may be noise spikes that appear interesting due to selection effects. The potential presence of such candidates calls for extra caution if claiming single-window TBO detections.
- ID:
- ivo://CDS.VizieR/J/ApJ/747/77
- Title:
- Thermonuclear X-ray bursts. II. Eddington limit
- Short Name:
- J/ApJ/747/77
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Time-resolved X-ray spectroscopy of thermonuclear bursts observed from low-mass X-ray binaries offer a unique tool to measure neutron-star masses and radii. In this paper, we continue our systematic analysis of all the X-ray bursts observed with Rossi X-ray Timing Explorer from X-ray binaries. We determine the events that show clear evidence for photospheric radius expansion and measure the Eddington limits for these accreting neutron stars using the bolometric fluxes attained at the touchdown moments of each X-ray burst. We employ a Bayesian technique to investigate the degree to which the Eddington limit for each source remains constant between bursts. We find that for sources with a large number of radius expansion bursts, systematic uncertainties are at a 5%-10% level. Moreover, in six sources with only pairs of Eddington-limited bursts, the distribution of fluxes is consistent with a ~10% fractional dispersion. This indicates that the spectroscopic measurements of neutron-star masses and radii using thermonuclear X-ray bursts can reach the level of accuracy required to distinguish between different neutron-star equations of state, provided that uncertainties related to the overall flux calibration of X-ray detectors are of comparable magnitude.
- ID:
- ivo://CDS.VizieR/J/ApJS/179/360
- Title:
- Thermonuclear X-ray bursts observed by RXTE
- Short Name:
- J/ApJS/179/360
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a sample of 1187 thermonuclear (type-I) X-ray bursts from public (archival) observations of 48 low-mass X-ray binaries accreting neutron stars by the Rossi X-ray Timing Explorer, spanning 1996 January - 2007 June 3. For each burst, we list results of analysis of data from the Proportional Counter Array, including observed count rates, time-resolved spectroscopy, evolution of the burst lightcurve, and details of the persistent flux and source spectral state at the time of the burst.