- ID:
- ivo://CDS.VizieR/J/ApJS/252/21
- Title:
- Multiwavelength survey of WR stars in LMC
- Short Name:
- J/ApJS/252/21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Surveys of Wolf-Rayet (WR) stars in the Large Magellanic Cloud (LMC) have yielded a fairly complete catalog of 154 known stars. We have conducted a comprehensive, multiwavelength study of the interstellar/circumstellar environments of WR stars, using the Magellanic Cloud Emission Line Survey images in the H{alpha}, [OIII], and [SII] lines; Spitzer Space Telescope 8 and 24{mu}m images; Blanco 4m Telescope H{alpha} CCD images; and Australian Telescope Compact Array + Parkes Telescope HI data cube of the LMC. We have also examined whether the WR stars are in OB associations, classified the HII environments of WR stars, and used this information to qualitatively assess the WR stars' evolutionary stages. The 30 Dor giant HII region has active star formation and hosts young massive clusters, thus we have made statistical analyses for 30 Dor and the rest of the LMC both separately and altogether. Due to the presence of massive young clusters, the WR population in 30 Dor is quite different from that from elsewhere in the LMC. We find small bubbles (<50pc diameter) around ~12% of WR stars in the LMC, most of which are WN stars and not in OB associations. The scarcity of small WR bubbles is discussed. Spectroscopic analyses of abundances are needed to determine whether the small WR bubbles contain interstellar medium or circumstellar medium. Implications of the statistics of interstellar environments and OB associations around WR stars are discussed. Multiwavelength images of each LMC WR star are presented.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/127/3273
- Title:
- Nearby galaxies HI observations
- Short Name:
- J/AJ/127/3273
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A survey of 329 nearby galaxies (redshift z<0.045) has been conducted to study the distribution of mass and light within spiral galaxies over a range of environments. The 18 observed clusters and groups span a range of richness, density, and X-ray temperature and are supplemented by a set of 30 isolated field galaxies. Optical spectroscopy taken with the 200inch (5m) Hale Telescope provides separately resolved H{alpha} and [NII] major-axis rotation curves for the complete set of galaxies, which are analyzed to yield velocity widths and profile shapes, extents, and gradients. HI line profiles provide an independent velocity width measurement and a measure of HI gas mass and distribution. I-band images are used to deconvolve profiles into disk and bulge components, to determine global luminosities and ellipticities, and to check morphological classification. These data are combined to form a unified data set ideal for the study of the effects of environment upon galaxy evolution.
- ID:
- ivo://CDS.VizieR/J/A+A/542/A110
- Title:
- Neutral gas in the Milky Way halo
- Short Name:
- J/A+A/542/A110
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an absorption-selected survey of CaII and NaI features located in the halo of the Milky Way using QSO absorption spectroscopy. We made use of the ESO data archive and retrieved all publically available absorption-line data for low- and high-redshift QSOs observed with the Ultraviolet and Visual Echelle Spectrograph (UVES) on the VLT. This enormous data archive (Spectral Quasar Absorption Database, SQUAD; PI: M.T. Murphy) provides high-quality spectral data for ~400 quasars and active galactic nuclei (AGN). Most of these spectra were taken in the UVES standard configuration using the 1" slit, providing a spectral resolution of R~45000 (corresponding to a velocity resolution of ~6.6km/sFWHM). The spectral coverage as well as the signal-to-noise ratio (S/N) varies substantially among the spectra, reflecting the various scientific goals of the original proposals. For several of the sight lines we performed deep (brightness temperature limit, Tb_lim_~30mK, angular resolution: 9' FWHM, spectral resolution: 0.5km/s FWHM) follow-up radio observations using the Effelsberg 100-m telescope to search for HI emission. Furthermore for a large fraction of the sight lines we obtained HI data from the new Galactic All-Sky survey (GASS, Tb_lim_~60mK, angular resolution: 15.6' FWHM, spectral resolution: 0.8km/s FWHM) and the Effelsberg-Bonn HI survey (EBHIS, Tb_lim_~90mK, angular resolution: 10.5' FWHM, spectral resolution: 1.2km/s FWHM). All HI data were corrected for stray radiation using software by P. Kalberla.
- ID:
- ivo://CDS.VizieR/J/A+AS/130/333
- Title:
- 2112 new 21-cm line measurements
- Short Name:
- J/A+AS/130/333
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalogue contains 2112 new 21-cm neutral hydrogen line measurements carried out with the meridian transit Nancay radiotelescope. Among these data we give also 213 new radial velocities which complement those listed in three previous papers of this series. Table2.dat is the list of corrected astrophysical HI-parameters (name, coordinates, systemic heliocentric velocity, line-width at two levels, log of maximum circular velocity, HI-flux and signal to noise ratio) The folder fig5 contains the files page01.ps, page02.ps ... corresponding to Figure 5, i.e. the HI-profiles of the galaxies listed in table2.dat.
- ID:
- ivo://CDS.VizieR/J/AJ/140/1093
- Title:
- NGC7332/7339 and NGC 1156 HI sources from AGES
- Short Name:
- J/AJ/140/1093
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Two 5deg^2^ regions around the NGC 7332/9 galaxy pair and the isolated galaxy NGC 1156 have been mapped in the 21cm line of neutral hydrogen (HI) with the Arecibo L-band Feed Array out to a redshift of ~0.065 (~20000km/s) as part of the Arecibo Galaxy Environment Survey. One of the aims of this survey is to investigate the environment of galaxies by identifying dwarf companions and interaction remnants; both of these areas provide the potential for such discoveries. The neutral hydrogen observations were complemented by optical and radio follow-up observations with a number of telescopes. A total of 87 galaxies were found, of which 39 (45%) were previously catalogued and 15 (17%) have prior redshifts. Two dwarf galaxies have been discovered in the NGC 7332 group and a single dwarf galaxy in the vicinity of NGC 1156. A parallel optical search of the area revealed one further possible dwarf galaxy near NGC 7332.
- ID:
- ivo://CDS.VizieR/J/A+A/618/A104
- Title:
- NGC3278, SN2009bb host, ATCA and MUSE data
- Short Name:
- J/A+A/618/A104
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The host galaxies of gamma-ray bursts (GRBs) have been claimed to have experienced a recent inflow of gas from the intergalactic medium. This is because their atomic gas distribution is not centred on their optical emission and because they are deficient in molecular gas given their high star-formation rates. Similar studies have not been conducted for host galaxies of relativistic supernovae (SNe), which may have similar progenitors. The potential similarity of the powering mechanisms of relativistic SNe and GRBs allowed us to make a prediction that relativistic SNe are born in environments similar to those of GRBs, i.e. rich in atomic gas. Here we embark on testing this hypothesis by analysing the properties of the host galaxy NGC 3278 of the relativistic SN 2009bb. This is the first time the atomic gas properties of a relativistic SN host is analysed and the first time resolved 21cm hydrogen line (HI) information is provided for a host of a SN of any type. We obtained radio observations with Australia Telescope Compact Array (ATCA) covering HI line; and optical integral field unit spectroscopy observations with Multi Unit Spectroscopic Explorer (MUSE) at the Very Large Telescope (VLT). Moreover, we analysed archival carbon monoxide (CO) and broad-band data for this galaxy. The atomic gas distribution of NGC3278 is not centred on the optical galaxy centre, but instead around a third of atomic gas resides in the region close to the SN position. This galaxy has a few times lower atomic and molecular gas masses than predicted from its star formation rate (SFR). Its specific star formation rate (sSFR=SFR/M*) is ~2-3 times higher than the main-sequence value, placing it at the higher end of the main sequence towards starburst galaxies. SN 2009bb exploded close to the region with the highest SFR density and the lowest age, as evident from high Halpha EW, corresponding to the age of the stellar population of ~5.5Myr. Assuming this timescale was the lifetime of the progenitor star, its initial mass would have been close to ~36M_{sun}_. As for GRB hosts, the gas properties of NGC3278 are consistent with a recent inflow of gas from the intergalactic medium, which explains the concentration of atomic gas close to the SN position and the enhanced SFR. Super-solar metallicity at the position of the SN (unlike for most of GRBs) may mean that relativistic explosions signal a recent inflow of gas (and subsequent star-formation), and their type (GRBs or SNe) is determined by either i) the metallicity of the inflowing gas (metal-poor gas results in a GRB explosion and metal-rich gas in a relativistic SN explosion without an accompanying GRB), or ii) by the efficiency of gas mixing (efficient mixing for SN hosts leading to quick disappearance of metal-poor regions), or iii) by the type of the galaxy (more metal-rich galaxies would result in only a small fraction of star-formation to be fuelled by metal-poor gas).
- ID:
- ivo://CDS.VizieR/J/A+A/586/A98
- Title:
- NGC 2683 VLA C and D datacubes
- Short Name:
- J/A+A/586/A98
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New deep VLA D array HI observations of the highly inclined nearby spiral galaxy NGC 2683 are presented. Archival C array data were processed and added to the new observations. To investigate the 3D structure of the atomic gas disk, we made different 3D models for which we produced model HI data cubes. The main ingredients of our best-fit model are (i) a thin disk inclined by 80{deg}; (ii) a crude approximation of a spiral and/or bar structure by an elliptical surface density distribution of the gas disk; (iii) a slight warp in inclination between 10kpc<=R<=20kpc (decreasing by 10{deg}); (iv) an exponential flare that rises from 0.5kpc at R=9kpc to 4kpc at R=15kpc, stays constant until R=22kpc, and decreases its height for R>22kpc; and (v) a low surface-density gas ring with a vertical offset of 1.3kpc. The slope of NGC 2683's flare is comparable, but somewhat steeper than those of other spiral galaxies. NGC 2683's maximum height of the flare is also comparable to those of other galaxies. On the other hand, a saturation of the flare is only observed in NGC 2683. Based on the comparison between the high resolution model and observations, we exclude the existence of an extended atomic gas halo around the optical and thin gas disk. Under the assumption of vertical hydrostatic equilibrium we derive the vertical velocity dispersion of the gas. The high turbulent velocity dispersion in the flare can be explained by energy injection by (i) supernovae; (ii) magneto-rotational instabilities; (iii) interstellar medium stirring by dark matter substructure; or (iv) external gas accretion. The existence of the complex large-scale warping and asymmetries favors external gas accretion as one of the major energy sources that drives turbulence in the outer gas disk. We propose a scenario where this external accretion leads to turbulent adiabatic compression that enhances the turbulent velocity dispersion and might quench star formation in the outer gas disk of NGC 2683.
- ID:
- ivo://CDS.VizieR/J/A+A/607/A43
- Title:
- NGC 4418/VV 655 HI images
- Short Name:
- J/A+A/607/A43
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The galaxy NGC4418 harbours a compact (<20pc) core with a very high bolometric luminosity (~10^11^L_{sun}_). As most of the galaxy's energy output comes from this small region, it is of interest to determine what fuels this intense activity. An interaction with the nearby blue irregular galaxy VV655 has been proposed, where gas aquired by NGC4418 could trigger intense star formation and/or black hole accretion in the centre. We aim to constrain the interaction hypothesis by studying neutral hydrogen structures which could reveal tails and debris connecting NGC4418 to the nearby galaxy VV655. We present observations at 1.4GHz with the Very Large Array (VLA) of radio continuum as well as emission and absorption from atomic hydrogen. Gaussian distributions are fitted to observed HI emission and absorption spectra.We estimate the star formation rate (SFR) of NGC4418 and VV655 from the 1.4GHz radio emission and compare with estimates from archival 70um Herschel observations.
- ID:
- ivo://CDS.VizieR/J/A+A/596/A60
- Title:
- NIBLES II. Arecibo follow-up observations
- Short Name:
- J/A+A/596/A60
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We obtained Arecibo HI line follow-up observations of 154 of the 2600 galaxies in the Nancay Interstellar Baryons Legacy Extragalactic Survey (NIBLES) sample. These observations are on average four times more sensitive than the original observations at the Nancay Radio Telescope. The main goal of this survey is to characterize the underlying HI properties of the NIBLES galaxies which were undetected or marginally detected at Nancay. Of the Nancay non-detections, 85% were either clearly or marginally detected at Arecibo, while 89% of the Nancay marginal detections were clearly detected. Based on the statistics of the detections relative to g-i color and r-band luminosity (Lr) distribution among our Arecibo observations, we anticipate ~60% of our 867 Nancay non-detections and marginal detections could be detected at the sensitivity of our Arecibo observations. Follow-up observations of our low luminosity (Lr<10^8.5^L_{sun}_) blue sources indicate that they have, on average, more concentrated stellar mass distributions than the Nancay detections in the same luminosity range, suggesting we may be probing galaxies with intrinsically different properties. These follow-up observations enable us to probe HI mass fractions, log(MHI/M*) 0.5dex and 1dex lower, on average, than the NIBLES and ALFALFA surveys respectively.
- ID:
- ivo://CDS.VizieR/J/A+A/595/A118
- Title:
- NIBLES. I. The Nancay HI survey
- Short Name:
- J/A+A/595/A118
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To investigate galaxy properties as a function of their total stellar mass, we obtained 21cm HI line observations at the 100-m class Nancay Radio Telescope of 2839 galaxies from the Sloan Digital Sky Survey (SDSS) in the Local Volume (900<cz<12000km/s), dubbed the Nancay Interstellar Baryons Legacy Extragalactic Survey (NIBLES) sample. They were selected evenly over their entire range of absolute SDSS z-band magnitudes (Mz~-13.5 to -24mag), which were used as a proxy for their stellar masses. In this paper, a first, global presentation of the observations and basic results is given; their further analysis will be presented in other papers in this series. The galaxies were originally selected based on their properties, as listed in SDSS DR5. Comparing this photometry to their total HI masses, we noted that, for a few percent, the SDSS magnitudes appeared severely misunderestimated, as confirmed by our re-measurements for selected objects. Although using the later DR9 results eliminated this problem in most cases, 384 still required manual photometric source selection. Usable HI spectra were obtained for 2600 of the galaxies, of which 1733 (67%) were clearly detected and 174 (7%) marginally. The spectra for 241 other observed galaxies could not be used for further analysis owing to problems with either the HI or the SDSS data. We reached the target number of about 150 sources per half-magnitude bin over the Mz range -16.5 to -23mag. Down to -21mag the overall detection rate is rather constant at the ~75% level but it starts to decline steadily towards the 30% level at -23mag. Making regression fits by comparing total HI and stellar masses for our sample, including our conservatively estimated HI upper limits for non-detections, we find the relationship log(MHI/M*)=-0.59log(M*)+5.05, which lies significantly below the relationship found in the MHI/M*-M* plane when only using HI detections.
