- ID:
- ivo://CDS.VizieR/J/A+A/568/A90
- Title:
- Herschel/SPIRE spectra in Arp 299
- Short Name:
- J/A+A/568/A90
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (Ultra) luminous infrared galaxies ((U)LIRGs) are nearby laboratories that allow us to study similar processes to those occurring in high redshift submillimeter galaxies. Understanding the heating and cooling mechanisms in these galaxies can give us insight into the driving mechanisms in their more distant counterparts. Molecular emission lines play a crucial role in cooling excited gas, and recently, with Herschel Space Observatory we have been able to observe the rich molecular spectrum. Carbon monoxide (CO) is the most abundant and one of the brightest molecules in the Herschel wavelength range. CO transitions from J=4-3 to 13-12 are observed with Herschel, and together, these lines trace the excitation of CO. We study Arp 299, a colliding galaxy group, with one component (A) harboring an active galactic nucleus and two more (B and C) undergoing intense star formation. For Arp 299 A, we present PACS spectrometer observations of high-J CO lines up to J=20-19 and JCMT observations of ^13^CO and HCN to discern between UV heating and alternative heating mechanisms.
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- ID:
- ivo://CDS.VizieR/J/ApJS/210/22
- Title:
- Herschel Stripe 82 survey (HerS) first catalog
- Short Name:
- J/ApJS/210/22
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first set of maps and band-merged catalog from the Herschel Stripe 82 Survey (HerS). Observations at 250, 350, and 500{mu}m were taken with the Spectral and Photometric Imaging Receiver (SPIRE) instrument aboard the Herschel Space Observatory. HerS covers 79deg^2^ along the SDSS Stripe 82 to an average depth of 13.0, 12.9, and 14.8mJy/beam (including confusion) at 250, 350, and 500{mu}m, respectively. HerS was designed to measure correlations with external tracers of the dark matter density field --either point-like (i.e., galaxies selected from radio to X-ray) or extended (i.e., clusters and gravitational lensing)-- in order to measure the bias and redshift distribution of intensities of infrared-emitting dusty star-forming galaxies and active galactic nuclei. By locating HerS in Stripe 82, we maximize the overlap with available and upcoming cosmological surveys. The band-merged catalog contains 3.3x10^4^ sources detected at a significance of >~3{sigma} (including confusion noise).
- ID:
- ivo://nasa.heasarc/hers82cat
- Title:
- Herschel Stripe 82 Survey (HerS) Point Source Catalog
- Short Name:
- HERS82CAT
- Date:
- 27 Sep 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This study presents the first set of maps and band-merged catalog from the Herschel Stripe 82 Survey (HerS). Observations at 250, 350, and 500 micron (µm) were taken with the Spectral and Photometric Imaging Receiver (SPIRE) instrument onboard the Herschel Space Observatory. HerS covers 79 square degrees along the SDSS Stripe 82 to an average depth of 13.0, 12.9, and 14.8 mJy beam<sup>-1</sup> (including confusion) at 250, 350, and 500 um, respectively. HerS was designed to measure correlations with external tracers of the dark matter density field, either point-like (i.e., galaxies selected from radio to X-ray) or extended (i.e., clusters and gravitational lensing), in order to measure the bias and redshift distribution of intensities of infrared-emitting dusty star-forming galaxies and active galactic nuclei. By locating HerS in Stripe 82, the authors maximize the overlap with available and upcoming cosmological surveys. The band-merged catalog contains 3.3 x 10<sup>4</sup> sources detected at a significance of >~ 3 sigma (including confusion noise). The maps and catalog are available at <a href="http://www.astro.caltech.edu/hers/">http://www.astro.caltech.edu/hers/</a>. This table contains the first HerS band-merged point source catalog based on observations covering 79 deg<sup>2</sup> in the equatorial Stripe 82, spanning 13 to 37 degrees (0<sup>h</sup> 54<sup>m</sup> to 2<sup>h</sup> 24<sup>m</sup> ) in RA, and -2 to +2 degrees in Declination. The SPIRE beams are 18.1, 25.2 and 36.6 arcseconds at 250, 350 and 500 um, respectively. The band-merged catalog was constructed, after filtering, with DESPHOT (Roseboom et al. 2010, MNRAS, 409, 48), using 250-um sources (extracted with STARFINDER: Diolaiti et al. 2000, A&AS, 147, 335) as positional priors. The authors included sources with S/N greater than 3, whose completeness is estimated to be 50% (see Figure 7 of the reference paper), with a false detection rate less than 1%, and which had reasonable residuals (i.e., chi<sup>2</sup> < 10). Next, they identified obviously extended sources - 24 in total - where their extended nature resulted in them being broken up into multiple components by the filter, and removed them. This results in a catalog with 32,815 sources at 250 um, of which 13,300 and 3,276 have similarly defined 3-sigma detections at 350 and 500 um, respectively. The authors expect a false positive rate of 1.2 +/- 0.2 deg<sup>-2</sup> : thus, across the 79 deg<sup>2</sup> of HerS, they expect 96 +/- 16 spurious sources. The following local extended sources were removed: <pre> Name, RA, DEC NGC 0493,20.537458,0.945361 UGC 00890,20.283333,1.373333 UGC 00892,20.319166,-0.544491 NGC 0428,18.232125,0.981556 NGC 0799,30.551407,-0.100629 NGC 0800,30.549358,-0.130432 NGC 0450,18.876840,-0.860973 NGC 0497,20.599064,-0.875207 NGC 0867,34.269910,1.244202 UGC 01725,33.607833,1.469833 NGC 0570,22.244325,-0.948996 UGC 00711,17.153750,1.641667 UGC 00726,17.489833,-1.749694 NGC 0550,21.677292,2.022361 NGC 0585,22.9255833,-0.9333056 UGC 01123,23.533209,-1.032286 2MASX J01434929-0048547,25.955091,-0.815256 NGC 0856,33.409831,-0.717287 UGC 01698,33.082019,-0.811513 CGCG 385-007,17.256708,1.378194 UGC 00790,18.657792,1.180167 2MFGC 01002,19.930083,1.630778 2MFGC 00979,19.642792,1.747889 UGC 00847,19.768317,-0.138572 </pre> This database table was created by the HEASARC in March 2014 based on a FITS file (v2.0, uploaded Nov 18, 2013, of hers.catalogue_3sig250_no_extended.fits) containing the catalog which was obtained from the HerS web site, viz., <a href="http://www.astro.caltech.edu/hers/Catalogs.html">http://www.astro.caltech.edu/hers/Catalogs.html</a>. Some of the values for the name parameter in the HEASARC's implementation of this table were corrected in April 2018. This is a service provided by NASA HEASARC .
- ID:
- ivo://CDS.VizieR/J/A+A/572/A90
- Title:
- Herschel-VVDS-CFHTLS-D1 detections
- Short Name:
- J/A+A/572/A90
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate of the properties of ~2000 Herschel/SPIRE far-infrared-selected galaxies from 0<z<4 in the CFHTLS-D1 field. Using a combination of extensive spectroscopy from the VVDS and ORELSE surveys, deep multiwavelength imaging from CFHT, VLA, Spitzer, XMM-Newton, and Herschel, and well-calibrated spectral energy distribution fitting, Herschel-bright galaxies are compared to optically-selected galaxies at a variety of redshifts. Herschel-selected galaxies are observed to span a range of stellar masses, colors, and absolute magnitudes equivalent to galaxies undetected in SPIRE. Though many Herschel galaxies appear to be in transition, such galaxies are largely consistent with normal star-forming galaxies when rest-frame colors are utilized. The nature of the star-forming "main sequence" is studied and we warn against adopting this framework unless the main sequence is determined precisely. Herschel galaxies at different total infrared luminosities (L_TIR_) are compared. Bluer optical colors, larger nebular extinctions, and larger contributions from younger stellar populations are observed for galaxies with larger L_TIR_, suggesting that low-L_TIR_ galaxies are undergoing rejuvenated starbursts while galaxies with higher L_TIR_ are forming a larger percentage of their stellar mass. A variety of methods are used to select powerful active galactic nuclei (AGN). Galaxies hosting all types of AGN are observed to be undergoing starbursts more commonly and vigorously than a matched sample of galaxies without powerful AGN and, additionally, the fraction of galaxies with an AGN increases with increasing SFR at all redshifts. At all redshifts (0<z<4) the most prodigious star-forming galaxies are found to contain the highest fraction of powerful AGN. For redshift bins that allow a comparison (z>0.5), the highest L_TIR_ galaxies in a given redshift bin are unobserved by SPIRE at subsequently lower redshifts, a trend linked to downsizing. In conjunction with other results, this evidence is used to argue for prevalent AGN-driven quenching in starburst galaxies across cosmic time.
- ID:
- ivo://CDS.VizieR/J/A+A/627/A100
- Title:
- HESS and Suzaku observations of Vela X
- Short Name:
- J/A+A/627/A100
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Pulsar Wind Nebulae (PWNe) represent the most prominent population of Galactic very-high-energy gamma-ray sources and are thought to be an efficient source of leptonic cosmic rays. Vela X is a nearby middle-aged PWN, which shows bright X-ray and TeV gamma-ray emission toward an elongated structure called the cocoon. Since TeV emission is likely inverse-Compton emission of electrons, predominantly from interactions with the cosmic microwave background, while X-ray emission is synchrotron radiation of the same electrons, we aim to derive the properties of the relativistic particles and of magnetic fields with minimal modelling. We use data from the Suzaku XIS to derive the spectra from three compact regions in Vela X covering distances from 0.3pc to 4pc from the pulsar along the cocoon. We obtain gamma-ray spectra of the same regions from H.E.S.S. observations and fit a radiative model to the multi-wavelength spectra. The TeV electron spectra and magnetic field strengths are consistent within the uncertainties for the three regions, with energy densities of the order 10^-12^erg/cm^-3^. The data indicate the presence of a cutoff in the electron spectrum at energies of 100TeV and a magnetic field strength of 6G. Constraints on the presence of turbulent magnetic fields are weak. The pressure of TeV electrons and magnetic fields in the cocoon is dynamically negligible, requiring the presence of another dominant pressure component to balance the pulsar wind at the termination shock. Sub-TeV electrons cannot account completely for the missing pressure, that may be provided either by relativistic ions or from mixing of the ejecta with the pulsar wind. The electron spectra are consistent with expectations from transport scenarios dominated either by advection via the reverse shock or by diffusion, but for the latter the role of radiative losses near the termination shock needs to be further investigated in the light of the measured cutoff energies. Constraints on turbulent magnetic fields and the shape of the electron cutoff can be improved by spectral measurements in the energy range >~10keV.
- ID:
- ivo://CDS.VizieR/J/A+A/612/A1
- Title:
- H.E.S.S. Galactic Plane Survey
- Short Name:
- J/A+A/612/A1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of the most comprehensive survey of the Galactic plane in very high-energy (VHE) gamma-rays, including a public release of Galactic sky maps, a catalog of VHE sources, and the discovery of 16 new sources of VHE gamma-rays. The High Energy Spectroscopic System (H.E.S.S.) Galactic plane survey (HGPS) was a decade-long observation program carried out by the H.E.S.S. I array of Cherenkov telescopes in Namibia from 2004 to 2013. The observations amount to nearly 2700 h of quality-selected data, covering the Galactic plane at longitudes from l=250{deg} to 65{deg} and latitudes |b|<=3. In addition to the unprecedented spatial coverage, the HGPS also features a relatively high angular resolution (0.08{deg}~5-arcmin mean point spread function 68% containment radius), sensitivity (1.5% Crab flux for point-like sources), and energy range (0.2-100TeV). We constructed a catalog of VHE gamma-ray sources from the HGPS data set with a systematic procedure for both source detection and characterization of morphology and spectrum. We present this likelihood- based method in detail, including the introduction of a model component to account for unresolved, large-scale emission along the Galactic plane. In total, the resulting HGPS catalog contains 78 VHE sources, of which 14 are not reanalyzed here, for example, due to their complex morphology, namely shell-like sources and the Galactic center region. Where possible, we provide a firm identification of the VHE source or plausible associations with sources in other astronomical catalogs. We also studied the characteristics of the VHE sources with source parameter distributions. 16 new sources were previously unknown or unpublished, and we individually discuss their identifications or possible associations. We firmly identified 31 sources as pulsar wind nebulae (PWNe), supernova remnants (SNRs), composite SNRs, or gamma-ray binaries. Among the 47 sources not yet identified, most of them (36) have possible associations with cataloged objects, notably PWNe and energetic pulsars that could power VHE PWNe.
- ID:
- ivo://CDS.VizieR/J/A+A/612/A3
- Title:
- HESS Galactic supernova remnants
- Short Name:
- J/A+A/612/A3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Shell-type supernova remnants (SNRs) are considered prime candidates for the acceleration of Galactic cosmic rays (CRs) up to the knee of the CR spectrum at E~=3x10^15^eV. Our Milky Way galaxy hosts more than 350 SNRs discovered at radio wavelengths and at high energies, of which 220 fall into the H.E.S.S. Galactic Plane Survey (HGPS) region. Of those, only 50 SNRs are coincident with a H.E.S.S source and in 8 cases the very high-energy (VHE) emission is firmly identified as an SNR. The H.E.S.S. GPS provides us with a legacy for SNR population study in VHE {gamma}-rays and we use this rich data set to extract VHE flux upper limits from all undetected SNRs. Overall, the derived flux upper limits are not in contradiction with the canonical CR paradigm. Assuming this paradigm holds true, we can constrain typical ambient density values around shell-type SNRs to n<=7cm^-3^ and electron-to-proton energy fractions above 10TeV to {epsilon}_ep_<=5x10^-3^. Furthermore, comparisons of VHE with radio luminosities in non-interacting SNRs reveal a behaviour that is in agreement with the theory of magnetic field amplification at shell-type SNRs.
- ID:
- ivo://nasa.heasarc/hesscat
- Title:
- HESS (High Energy Stereoscopic System) Source Catalog
- Short Name:
- HESSCAT
- Date:
- 27 Sep 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- H.E.S.S. is a system of Imaging Atmospheric Cherenkov Telescopes for the investigation of cosmic gamma rays in the 100 GeV energy range. The name H.E.S.S. stands for High Energy Stereoscopic System, and should also remind us of Victor Hess, who received in 1936 the Nobel Prize in Physics for his discovery of cosmic radiation. The instrument allows us to explore gamma-ray sources with intensities at a level of a few thousandth parts of the flux of the Crab nebula. H.E.S.S. is located in Namibia, near the Gamsberg, an area well known for its excellent optical quality. The first of the four telescopes of Phase I of the H.E.S.S. project went into operation in Summer 2002; all four were operational in December 2003, and were officially inaugurated on September 28, 2004. In recognition of its scientific results, H.E.S.S. was awarded the 2006 Descartes Prize for Research of the European Commission. This database table, first created in April 2008, contains the H.E.S.S. source list created by Dr. W. Hofmann and is based on the HTML table at <a href="http://www.mpi-hd.mpg.de/hfm/HESS/public/HESS_catalog.htm">http://www.mpi-hd.mpg.de/hfm/HESS/public/HESS_catalog.htm</a>. The latter table is updated regularly and this HEASARC table will be updated within one week of any updates. This is a service provided by NASA HEASARC .
- ID:
- ivo://CDS.VizieR/J/A+A/621/A116
- Title:
- HESS J1825-137 particle transport
- Short Name:
- J/A+A/621/A116
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a detailed view of the pulsar wind nebula (PWN) HESS J1825--137. We aim to constrain the mechanisms dominating the particle transport within the nebula, accounting for its anomalously large size and spectral characteristics. The nebula is studied using a deep exposure from over 12 years of H.E.S.S. I operation, together with data from H.E.S.S. II improving the low energy sensitivity. Enhanced energy- dependent morphological and spatially-resolved spectral analyses probe the Very High Energy (VHE, E>0.1TeV) gamma-ray properties of the nebula. The nebula emission is revealed to extend out to 1.5 degrees from the pulsar, ~1.5 times further than previously seen, making HESS J1825-137, with an intrinsic diameter of ~100pc, potentially the largest gamma-ray PWN currently known. Characterisation of the nebula's strongly energy-dependent morphology enables the particle transport mechanisms to be constrained. A dependence of the nebula extent with energy of R{prop.to} E^alpha^ with alpha=-0.29+/-0.04(stat)+/-0.05(sys) disfavours a pure diffusion scenario for particle transport within the nebula. The total gamma-ray flux of the nebula above 1~TeV is found to be (1.12+/-0.03(stat)+/-0.25(sys))x10^-11^cm^-2^s^-1^, corresponding to ~64% of the flux of the Crab Nebula. HESS J1825-137 is a PWN with clear energy-dependent morphology at VHE gamma-ray energies. This source is used as a laboratory to investigate particle transport within middle-aged PWNe. Deep observations of this highly spatially-extended PWN enable a spectral map of the region to be produced, providing insights into the spectral variation within the nebula.
- ID:
- ivo://CDS.VizieR/J/A+A/484/721
- Title:
- HES survey. IV. Candidate metal-poor stars
- Short Name:
- J/A+A/484/721
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the quantitative methods used for selecting candidate metal-poor stars in the Hamburg/ESO objective-prism survey (HES). The selection is based on the strength of the CaII K line, B-V colors (both measured directly from the digital HES spectra), as well as J-K colors from the 2 Micron All Sky Survey. The KP index for CaII K can be measured from the HES spectra with an accuracy of 1.0{AA}, and a calibration of the HES B-V colors, using CCD photometry, yields a 1-sigma uncertainty of 0.07mag for stars in the color range 0.3<B-V<1.4.