- ID:
- ivo://CDS.VizieR/J/A+A/564/A111
- Title:
- Galactic plane dust temperature maps with Herschel
- Short Name:
- J/A+A/564/A111
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Dust grains absorb the interstellar far ultra-violet and visible photons and re-emit them in far-infrared (FIR) wavebands. The dust FIR continuum can be predicted by a grid of models using various values of the interstellar radiation field. We analyze the dust continuum emission in two Hi-GAL science-demonstration phase (SDP) fields using both the radiative transfer code, Cloudy, and the DustEM dust model, to explore the effect of radiative transfer on dust temperature. The 500um sub-millimeter excess emission and the very small grain (VSG) contribution to the 70um intensity are investigated by spectral energy distribution (SED) fitting using the Cloudy model.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/714/1096
- Title:
- Galactic planetary nebulae
- Short Name:
- J/ApJ/714/1096
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use an extended and homogeneous data set of Galactic planetary nebulae (PNe) to study the metallicity gradients and the Galactic structure and evolution. The most up-to-date abundances, distances (calibrated with Magellanic Cloud PNe), and other parameters have been employed, together with a novel homogeneous morphological classification, to characterize the different PN populations. We studied the {alpha}-element distribution within the Galactic disk, and found that the best selected disk population (i.e., excluding bulge and halo component), together with the most reliable PN distance scale yields to a radial oxygen gradient of {Delta}log(O/H)/{Delta}R_G_=-0.023+/-0.006dex/kpc for the whole disk sample, and of {Delta}log(O/H)/{Delta}R_G_=-0.035+/-0.024, -0.023+/-0.005, and -0.011+/-0.013dex/kpc, respectively for Type I, II, and III PNe, i.e., for high-, intermediate-, and low-mass progenitors. We also extend the Galactic metallicity gradient comparison by revisiting the open cluster [Fe/H] data from high resolution spectroscopy.
- ID:
- ivo://CDS.VizieR/J/PASJ/52/631
- Title:
- Galactic plane VERA survey
- Short Name:
- J/PASJ/52/631
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In order to search for new VLBI sources in the galactic plane that can be used as phase reference sources in differential VLBI, we conducted 22GHz observations of radio sources in the galactic plane using the Japanese VLBI Network (J-Net). We have observed 267 VLBI source candidates selected from existing radio surveys and have detected 93 sources at a signal-to-noise ratio larger than 5. While 42 of the 93 detected sources had already been detected with VLBI at relatively lower frequency (typically 2 to 8GHz), the remaining 51 are found to be new VLBI sources detected for the first time. These are located within |b|<=5{deg}, and have a large number of galactic maser sources around them. Thus, they are potential candidates for phase reference sources for VLBI Exploration of Radio Astrometry (VERA), which is the first VLBI array dedicated to phase-referencing VLBI astrometry aimed at measuring the parallax and proper motion of maser sources in the whole Galaxy.
- ID:
- ivo://CDS.VizieR/J/AJ/96/1655
- Title:
- Galactic plane VLA survey
- Short Name:
- J/AJ/96/1655
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results from a continuum VLA snapshot survey of the galactic plane in the longitude range 0{deg}<=l<=90{deg} at 1.5GHz. Observations were taken every 0.5{deg} in longitude at b=0{deg}. Most fields are complete to about 30mJy peak flux density. The positions, peak, and total flux density of 471 compact sources (<30") have been measured. A complete sample of 329 sources is defined. An excess of sources above that expected from extragalactic source counts is seen for l<40{deg} at all flux-density intervals. We find 86 compact sources that are within 2.4arcmin of a source in the recent radio recombination-line survey of Lockman (1989ApJS...71..469L) Source counts excluding these 86 sources agree with extragalactic source counts for all flux-density and longitude intervals. there may only be a small number of galactic objects present in this survey that remain unidentified as such.
- ID:
- ivo://CDS.VizieR/J/ApJ/723/1019
- Title:
- Galactic SFR and gas surface densities
- Short Name:
- J/ApJ/723/1019
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the relation between star formation rate (SFR) and gas surface densities in Galactic star-forming regions using a sample of young stellar objects (YSOs) and massive dense clumps. Our YSO sample consists of objects located in 20 large molecular clouds from the Spitzer cores to disks (c2d; Evans, 2009, Cat. J/ApJS/181/321) and Gould's Belt (GB) survey (L. Allen et al. 2010, in preparation). These data allow us to probe the regime of low-mass star formation, essentially invisible to tracers of high-mass star formation used to establish extragalactic SFR-gas relations. We estimate the gas surface density ({Sigma}_gas_) from extinction (A_V_) maps and YSO SFR surface densities ({Sigma}_SFR_) from the number of YSOs, assuming a mean mass and lifetime. We also divide the clouds into evenly spaced contour levels of A_V_, counting only Class I and Flat spectral energy distribution YSOs, which have not yet migrated from their birthplace. For a sample of massive star-forming clumps, we derive SFRs from the total infrared luminosity and use HCN gas maps to estimate gas surface densities. We find that c2d and GB clouds lie above the extragalactic SFR-gas relations (e.g., Kennicutt-Schmidt law) by factors of up to 17. We use ^12^CO and ^13^CO gas maps of the Perseus and Ophiuchus clouds from the COMPLETE survey (Ridge et al. 2006AJ....131.2921R) to estimate gas surface densities and compare to measurements from A_V_ maps.
- ID:
- ivo://CDS.VizieR/J/MNRAS/458/3411
- Title:
- Galactic SNR ^44^Ti survey
- Short Name:
- J/MNRAS/458/3411
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the results of the deepest Galactic plane (|b|<17.5{deg}) survey in the 67.9 and 78.4keV nuclear de-excitation lines of titanium-44 (^44^Ti) performed using the data acquired with the IBIS/ISGRI instrument onboard the INTEGRAL satellite during 12yr of operation. The peak sensitivity of our survey reached an unprecedented level of 4.8x10^-6^ph/cm2/s (3{sigma}) that improves the sensitivity of the survey done by Compton Gamma-Ray Observatory/COMPTEL by a factor of ~5. As a result, constraining upper limits for all sources from the catalogue of Galactic supernova remnants (SNRs; Green, 2014, Cat. VII/272) are derived. These upper limits can be used to estimate the exposure needed to detect ^44^Ti emission from any known SNR using existing and prospective X- and gamma-ray telescopes. Among the youngest Galactic SNRs, only Cas A shows significant ^44^Ti emission flux in good agreement with the NuSTAR measurements. We did not detect any other sources of titanium emission in the Galactic plane at significance level higher than 5{sigma} confirming previous claims of the rarity of such ^44^Ti-producing SNRs.
- ID:
- ivo://CDS.VizieR/J/MNRAS/432/3349
- Title:
- Galactic star clusters structural parameters
- Short Name:
- J/MNRAS/432/3349
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper, we investigate the nature of 27 star cluster candidates, most of them projected towards the Galactic anticentre. We derive fundamental parameters for 20 confirmed clusters, among these 7 are new identifications. Four of the remaining are uncertain cases that require deeper photometry to establish their nature, and four are probably field fluctuations. In addition, we provide a partial census of the open clusters towards the Galactic anticentre. We also include in this study some interesting objects outside the anticentre region, in the second and third Galactic quadrants, mainly in the Perseus and outer arms. These clusters confirm the extension of the outer arm along the third quadrant. We also point out that the embedded cluster FSR 486, at a distance of 7.2+/-1.3kpc from the Sun, is projected on the line of sight of the Local Group irregular dwarf galaxy IC 10. Thus, part of the unusual properties of IC 10 may be explained by a Galactic contamination. We point out the importance of embedded clusters in tracing the spiral structure.
- ID:
- ivo://CDS.VizieR/J/AJ/128/1177
- Title:
- Galactic stellar abundances
- Short Name:
- J/AJ/128/1177
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To compare the chemistries of stars in the Milky Way dwarf spheroidal (dSph) satellite galaxies with stars in the Galaxy, we have compiled a large sample of Galactic stellar abundances from the literature. When kinematic information is available, we have assigned the stars to standard Galactic components through Bayesian classification based on Gaussian velocity ellipsoids. As found in previous studies, the [{alpha}/Fe] ratios of most stars in the dSph galaxies are generally lower than similar metallicity Galactic stars in this extended sample.
229. Galactic Worms
- ID:
- ivo://CDS.VizieR/J/ApJ/390/108
- Title:
- Galactic Worms
- Short Name:
- J/ApJ/390/108
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A catalog of candidates for the Galactic Worms that are possibly the walls surrounding the superbubbles is compiled; 118 isolated structures that appear both in HI and in IR (60 and 100{mu}m). 52 are possibly associated with HII regions. It is found that the 100-{mu}m emissivity increases systematically toward the Galactic interior, which is consistent with the increase of the general interstellar radiation field. The 100-{mu}m emissivity of the structures associated with the HII regions is larger than that of the structures without associated HII regions. The 60-100{mu}m ratio is large, 0.28+/-0.03, which may indicate that the grains associated with the atomic gas have a relatively large population of small grains. 35 structures appear in the 408MHz continuum. The IR and the radio continuum properties suggest that the 408MHz continuum emission in those structures is very likely thermal. The implications of these results on the ionization of gas far from the Galactic plane are discussed.
- ID:
- ivo://CDS.VizieR/J/MNRAS/465/3203
- Title:
- GALAH observational overview
- Short Name:
- J/MNRAS/465/3203
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Galactic Archaeology with HERMES (GALAH) Survey is a massive observational project to trace the Milky Way's history of star formation, chemical enrichment, stellar migration and minor mergers. Using high-resolution (R~28,000) spectra taken with the High Efficiency and Resolution Multi-Element Spectrograph (HERMES) instrument at the Anglo-Australian Telescope (AAT), GALAH will determine stellar parameters and abundances of up to 29 elements for up to one million stars. Selecting targets from a colour-unbiased catalogue built from 2MASS, APASS and UCAC4 data, we expect to observe dwarfs at 0.3 to 3kpc and giants at 1 to 10kpc. This enables a thorough local chemical inventory of the Galactic thin and thick disks, and also captures smaller samples of the bulge and halo. In this paper we present the plan, process and progress as of early 2016 for GALAH survey observations. In our first two years of survey observing we have accumulated the largest high-quality spectroscopic data set at this resolution, over 200,000 stars. We also present the first public GALAH data catalogue: stellar parameters (Teff, log(g), [Fe/H], [alpha/Fe]), radial velocity, distance modulus and reddening for 10680 observations of 9860 Tycho-2 stars that may be included in the first Gaia data release.
