- ID:
- ivo://CDS.VizieR/J/ApJ/459/686
- Title:
- Energy Deposition in Interstellar Dust Grains
- Short Name:
- J/ApJ/459/686
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog contains calculated tables of the energy deposition into dust grains by photons with energies between 10 eV and 1 MeV. The tables give the deposition for 60 different energies and 15 dust grain sizes. Tables for both silicate and graphite grains are presented. Photoelectric absorption, auger electrons, and Compton scattering are used in the calculations, which were done with a Mie code when necessary and a particle approach when appropriate. The file graphite.dat corresponds to Table 5.1 in the source reference. Silicate.dat corresponds to Table 5.2.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/711/1236
- Title:
- Equivalent width of H_2_ from FUSE
- Short Name:
- J/ApJ/711/1236
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Far Ultraviolet Spectroscopic Explorer (FUSE) has allowed precise determinations of the column densities of molecular hydrogen (H_2_) in Galactic lines of sight with a wide range of pathlengths and extinction properties. However, survey studies of lines of sight with greater extinction have been mostly restricted to the low-J states (lower total angular momentum) in which most molecular hydrogen is observed. This paper presents a survey of column densities for the molecular hydrogen in states of greater rotational excitation (J>=2) in Galactic lines of sight with log N(H_2_)>~20. This study is comprehensive through the highest excited state detectable in each line of sight. J=5 is observed in every line of sight, and we detect J=7 in four lines of sight, J=8 in one line of sight, and vibrationally excited H_2_ in two lines of sight.
- ID:
- ivo://CDS.VizieR/J/A+A/555/A25
- Title:
- Equivalent widths of DIBs
- Short Name:
- J/A+A/555/A25
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Stellar spectroscopic surveys may bring useful statistical information on the links between diffuse interstellar bands (DIBs) and the interstellar environment. DIB databases can also be used as a complementary tool for locating interstellar (IS) clouds. Our goal is to develop fully automated methods of DIB measurements to be applied to extensive data from stellar surveys. We present a method that is appropriate for early-type nearby stars, along with its application to high-resolution spectra of ~130 targets recorded with the ESO FEROS spectrograph and comparisons with other determinations. Using a DIB average profile deduced from the most reddened stars, we performed an automated fitting of a combination of a smooth stellar continuum, the DIB profile, and, when necessary, a synthetic telluric transmission.
- ID:
- ivo://CDS.VizieR/J/ApJ/850/194
- Title:
- Equivalent widths of 8 DIBs for 186 O & B stars
- Short Name:
- J/ApJ/850/194
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the behavior of eight diffuse interstellar bands (DIBs) in different interstellar environments, as characterized by the fraction of hydrogen in molecular form (f_H2_), with comparisons to the corresponding behavior of various known atomic and molecular species. The equivalent widths of the five "normal" DIBs ({lambda}{lambda}5780.5, 5797.1, 6196.0, 6283.8, and 6613.6), normalized to E_B-V_, show a "lambda-shaped" behavior: they increase at low f_H2_, peak at f_H2_~0.3, and then decrease. The similarly normalized column densities of Ca, Ca+, Ti+, and CH+ also decline for f_H2_>0.3. In contrast, the normalized column densities of Na, K, CH, CN, and CO increase monotonically with fH2, and the trends exhibited by the three C_2_ DIBs ({lambda}{lambda}4726.8, 4963.9, and 4984.8) lie between those two general behaviors. These trends with f_H2_ are accompanied by cosmic scatter, the dispersion at any given f_H2_ being significantly larger than the individual errors of measurement. The lambda-shaped trends suggest the balance between creation and destruction of the DIB carriers differs dramatically between diffuse atomic and diffuse molecular clouds; additional processes aside from ionization and shielding are needed to explain those observed trends. Except for several special cases, the highest W{lambda}(5780)/W{lambda}(5797) ratios, characterizing the so-called "sigma-zeta effect," occur only at f_H2_<0.2. We propose a sequence of DIBs based on trends in their pair-wise strength ratios with increasing f_H2_. In order of increasing environmental density, we find the {lambda}6283.8 and {lambda}5780.5 DIBs, the {lambda}6196.0 DIB, the {lambda}6613.6 DIB, the {lambda}5797.1 DIB, and the C_2_ DIBs.
- ID:
- ivo://CDS.VizieR/J/ApJ/884/11
- Title:
- Exploring 6 AGN dusty torus models. II.
- Short Name:
- J/ApJ/884/11
- Date:
- 04 Dec 2021
- Publisher:
- CDS
- Description:
- This is the second in a series of papers devoted to exploring a set of six dusty models of active galactic nuclei (AGN) with available spectral energy distributions. These models are the smooth torus by Fritz+ (2006MNRAS.366..767F), the clumpy torus by Nenkova+ (2008ApJ...685..147N and 2008ApJ...685..160N), the clumpy torus by Honig & Kishimoto (2010A&A...523A..27H), the two-phase torus by Siebenmorgen+ (2015A&A...583A.120S), the two-phase torus by Stalevski+ (2012MNRAS.420.2756S and 2016MNRAS.458.2288S), and the wind model by Honig & Kishimoto (2017ApJ...838L..20H). The first paper explores discrimination among models and the parameter restriction using synthetic spectra. Here we perform spectral fitting of a sample of 110 AGN drawn from the Swift/BAT survey with Spitzer/IRS spectroscopic data. The aim is to explore which is the model that describes better the data and the resulting parameters. The clumpy wind-disk model by Honig & Kishimoto provides good fits for ~50% of the sample, and the clumpy torus model by Nenkova+ is good at describing ~30% of the objects. The wind-disk model by Honig & Kishimoto is better for reproducing the mid-infrared spectra of type 1 Seyferts (with 60% of the type 1 Seyferts well reproduced by this model compared to the 10% well represented by the clumpy torus model by Nenkova+), while type 2 Seyferts are equally fitted by both models (roughly 40% of the type 2 Seyferts). Large residuals are found irrespective of the model used, indicating that the AGN dust continuum emission is more complex than predicted by the models or that the parameter space is not well sampled. We found that all the resulting parameters for our AGN sample are roughly constrained to 10%-20% of the parameter space. Contrary to what is generally assumed, the derived outer radius of the torus is smaller (reaching up to a factor of ~5 smaller for 10pc tori) for the smooth torus by Fritz+ and the two-phase torus by Stalevski+ than the one derived from the clumpy torus by Nenkova+ Covering factors and line-of-sight viewing angles strongly depend on the model used. The total dust mass is the most robust derived quantity, giving equivalent results for four of these models.
- ID:
- ivo://CDS.VizieR/J/BaltA/11/441
- Title:
- Extinction along Cam and Per border
- Short Name:
- J/BaltA/11/441
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Interstellar extinction in a ~100 sq. degree area at the Camelopardalis and Perseus border is investigated. The study is based on the results of photoelectric photometry of 455 stars in the seven-color Vilnius photometric system published earlier. The nearest 100 stars with Hipparcos parallaxes show that the extinction starts to grow at a distance of 110-150pc. At a distance of 1 kpc the extinction A_v_ is within 1.2 and 2.4mag. At larger distances the extinction determination is affected by the limiting magnitude effect. At distances >1.5kpc a number of O-B stars with the extinctions between 2 and 4mag are found.
- ID:
- ivo://CDS.VizieR/J/ApJ/517/264
- Title:
- Extinction in the Taurus dark cloud complex
- Short Name:
- J/ApJ/517/264
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a study of the detailed distribution of extinction in a region of the Taurus dark cloud complex. Our study uses new BVR images of the region, spectral classification data for 95 stars, and IRAS Sky Survey Atlas (ISSA) 60 and 100 {mu}m images. We study the extinction of the region in four different ways, and we present the first intercomparison of all these methods, which are as follows: (1) using the color excess of background stars for which spectral types are known, (2) using the ISSA 60 and 100 {mu}m images, (3) using star counts, and (4) using an optical (V and R) version of the average color excess method used by Lada et al. We find that all four methods give generally similar results - with important exceptions. As expected, all the methods show an increase in extinction due to dense dusty regions (i.e., dark clouds and IRAS cores) and a general increase in extinction with increasing declination, due to a larger content of dust in the northern regions of the Taurus dark cloud complex. Some of the discrepancies between the methods are caused by assuming a constant dust temperature for each line of sight in the ISSA extinction maps and not correcting for unexpected changes in the background stellar population (i.e., the presence of a cluster or Galactic gradients in the stellar density and average V-R color).
- ID:
- ivo://CDS.VizieR/J/A+A/533/A38
- Title:
- Extinction map of OMC-1
- Short Name:
- J/A+A/533/A38
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Orion Nebula and its associated young stellar cluster are located at the front-side of the optically thick OMC-1 molecular cloud. In order to disentangle the cluster members from background contamination, it is important to know the extinction provided by the OMC-1, which is poorly known, the available measurements yielding contradictory results. Our main goal is to derive a new extinction map of the OMC-1, obtaining information about the structure of the OMC-1 and the Orion Nebula Cluster. The most recent near-infrared catalog of stars is used to study the distribution of reddening across a 0.3deg^2^ area covering the Orion Nebula Cluster. On the basis of the observed (H,H-Ks) diagram, we establish a criterion for disentangling contaminants from bona-fide cluster members. For contaminant stars, interstellar reddenings are estimated by comparison with a synthetic galactic model. A statistical analysis is then performed to consistently account for local extinction, reddening and star-counts analysis. We derive the extinction map of the OMC-1 with angular resolution <5'. We also assemble a sample of candidate cluster members, for which we measure the extinction provided by the nebular environment. These extinction measurements are analyzed similarly to the contaminant sample, and an extinction map of the Orion Nebula is derived. The extinction provided by the OMC-1 is variable on spatial scales of a few arcminutes, while showing a general increase from the outskirts (A_V_~6) to the direction of the Trapezium asterism (A_V_>30). The Orion Nebula extinction map is more irregular and optically thinner, with Av of the order of a few magnitudes. Both maps are consistent with the optical morphology, in particular the Dark Bay to the north-east of the Trapezium. Both maps also show the presence of a north-south high-density ridge, which confirms the filamentary structure of the Orion molecular complex inside which star formation is still taking place.
- ID:
- ivo://CDS.VizieR/J/A+A/632/A101
- Title:
- Extremely high-velocity jets in Serpens
- Short Name:
- J/A+A/632/A101
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- ALMA observations of four molecular transitions, CO 2-1, SiO 5-4, H_2_CO 3_03_-2_02_ in Band 6 (ALMA project 2013.1.00726.S; PI: C. Hull) and HCN 1-0 observed in Band 3 (ALMA project 2016.1.00710.S; PI: C. Hull) are presented. The synthesized beam of the observations is between 0.3 and 0.6 arcsec, corresponding to 130-260au at the distance to Serpens Main. The largest recoverable scale in the data is 5 arcsec and 12 arcsec (2150 and 4960au) for Band 3 and Band 6, respectively. The spectral resolution of the observations differs between the spectral windows, ranging from 0.04 to 0.3km/s. For both bands, only 12-m array data were used. The Band 6 data were obtained in two configurations (C43-1 and C43-4 with resolutions of 1.1 and 0.3 arcsec, respectively, and the final images are produced from the combined datasets.
- ID:
- ivo://CDS.VizieR/J/other/Galax/7.43
- Title:
- Faraday rotation of extended emission
- Short Name:
- J/other/Galax/7.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Galactic magnetic field is an integral constituent of the interstellar medium (ISM), and knowledge of its structure is crucial to understanding Galactic dynamics. The Rotation Measures (RM) of extragalactic (EG) sources have been the basis of comprehensive Galactic magnetic field models. Polarised extended emission (XE) is also seen along lines of sight through the Galactic disk, and also displays the effects of Faraday rotation. Our aim is to investigate and understand the relationship between EG and XE RMs near the Galactic plane, and to determine how the XE RMs, a hitherto unused resource, can be used as a probe of the large-scale Galactic magnetic field. We used polarisation data from the Canadian Galactic Plane Survey (CGPS), observed near 1420 MHz with the Dominion Radio Astrophysical Observatory (DRAO) Synthesis Telescope. We calculated RMs from a linear fit to the polarisation angles as a function of wavelength squared in four frequency channels, for both the EG sources and the XE. Across the CGPS area, l=55 to l=193 degrees, b=-3 to b=5 degrees, the RMs of the XE closely track the RMs of the EG sources, with XE RMs about half the value of EG-source RMs. The exceptions are places where large local HII complexes heavily depolarise more distant emission. We conclude that there is valuable information in the XE RM dataset. The factor of 2 between the two types of RM values is close to that expected from a Burn slab model of the ISM. This result indicates that, at least in the outer Galaxy, the EG and XE sources are likely probing similar depths, and that the Faraday rotating medium and the synchrotron emitting medium have similar variation with galactocentric distance.
