- ID:
- ivo://CDS.VizieR/J/AJ/90/2221
- Title:
- UMi dwarf galaxy BV photometry
- Short Name:
- J/AJ/90/2221
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have constructed a color-magnitude diagram of the Ursa Minor dwarf spheroidal to m_V_=24.8mag from charged-coupled device (CCD) observations with the Kitt Peak 4 m telescope. The main-sequence turnoff is easily visible. Fits to evolutionary isochrones and the globular M92 indicate that Ursa Minor has an age and metal abundance very similar to that of the latter cluster. No evidence for stars younger than about 16 billion years is seen, with the possible exception of approximately 20 stars believed to be blue stragglers. Ursa Minor is therefore an extreme-age galaxy, unlike superficially similar objects such as the Carina dwarf. Indeed, Ursa Minor may be the only outer-halo spheroidal whose stellar content lives up to the classical ideals of a Population II system. A distance modulus of (m-M)_0_=19.0mag is derived from a sliding fit to the M92 ridge lines. However, this modulus is uncertain by ~0.1mag, for the horizontal branch in our color-magnitude diagram is poorly populated. The ratio of blue stragglers to anomalous Cepheids in Ursa Minor is estimated to be ~100, a number that may provide an important constraint on binary models for the origin of these stars. A surprising result of our study is the discovery of clumpiness in the distribution of stars. This finding may give more weight to the idea that dwarf spheroidal galaxies were previously dwarf irregular galaxies, although clearly, if so, Ursa Minor must have lost its gaseous content very soon after formation.
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23092. 11.5um image of NGC 835
- ID:
- ivo://CDS.VizieR/J/A+A/587/A1
- Title:
- 11.5um image of NGC 835
- Short Name:
- J/A+A/587/A1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Obscured active galactic nuclei (AGNs) are thought to be very common in the Universe. Observations and surveys have shown that the number of sources increases for near galaxies and at the low-luminosity regime (the so-called LLAGNs). Furthermore, many AGNs show changes in their obscuration properties at X-rays that may suggest a configuration of clouds very close to the accretion disk. However, these variations could also be due to changes in the intrinsic continuum of the source. It is therefore important to study nearby AGN to better understand the locus and distribution of clouds in the neighbourhood of the nucleus. We aim to study the nuclear obscuration of LLAGN NGC 835 and its extended emission using mid-infrared observations. We present sub-arcsecond-resolution mid-infrared 11.5um imaging of the LLAGN galaxy NGC 835 obtained with the instrument CanariCam in the Gran Telescopio CANARIAS (GTC), archival Spitzer/IRS spectroscopy, and archival Chandra data observed in 2000, 2008, and 2013.
- ID:
- ivo://CDS.VizieR/J/A+A/561/A49
- Title:
- 867um image of SBS 0335-052 with ALMA
- Short Name:
- J/A+A/561/A49
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Atacama Large Millimeter/submillimeter Array (ALMA) Cycle 0 Band 7 observations of an extremely metal-poor dwarf starburst galaxy in the Local Universe, SBS 0335-052 (12+log(O/H)~7.2). With these observations, dust is detected at 870um (ALMA Band 7), but 87% of the flux in this band is due to free-free emission from the starburst.
23094. 8.6um imaging of 47 Tuc
- ID:
- ivo://CDS.VizieR/J/A+A/537/A2
- Title:
- 8.6um imaging of 47 Tuc
- Short Name:
- J/A+A/537/A2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- There is an ongoing debate regarding the onset luminosity of dusty mass loss in population-II red giant stars. We present VLT/VISIR mid-infrared (MIR) 8.6um imaging of 47 Tuc, the centre of attention of a number of space-based Spitzer observations and studies. The VISIR high-resolution (diffraction limited) observations allow excellent matching to existing optical Hubble Space Telescope catalogues. The optical-MIR coverage of the inner core of the cluster provide the cleanest possible blending-free sampling of the upper 3mag of the giant branch. Our diagrams show no evidence of faint giants with MIR-excess. A combined near/mid-infrared diagram additionally confirms the near absence of dusty red giants. Dusty red giants and asymptotic giant stars are confined to the 47 Tuc long-period variable population. In particular, dusty red giants are limited to the upper one N8.6um magnitude below the giant branch tip. This particular luminosity level corresponds to ~1000L_{sun}_, which was suggested in previous determinations to mark the onset of dusty mass loss. Interestingly, starting from this luminosity level we detected a gradual deviation between the colours of red giants and the theoretical isochrones.
- ID:
- ivo://CDS.VizieR/J/A+A/475/791
- Title:
- 12um ISOCAM survey of the ESO-Sculptor field
- Short Name:
- J/A+A/475/791
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a detailed reduction of a mid-infrared 12um (LW10 filter) ISOCAM open time observation performed on the ESO-Sculptor Survey field (Arnouts et al., 1997A&AS..124..163A). A complete catalogue of 142 sources (120 galaxies and 22 stars), detected with high significance (equivalent to 5{sigma}), is presented above an integrated flux density of 0.31mJy. Star/galaxy separation is performed by a detailed study of colour-colour diagrams. The catalogue is complete to 1mJy and, below this flux density, the incompleteness is corrected using two independent methods. The first method uses stars and the second uses optical counterparts of the ISOCAM galaxies; these methods yield consistent results. We also apply an empirical flux density calibration using stars in the field. For each star, the 12um flux density is derived by fitting optical colours from a multi-band {chi}^2^ to stellar templates (BaSel-2.0) and using empirical optical-IR colour-colour relations. This article is a companion analysis to our 2007 paper (Rocca-Volmerange et al. 2007A&A...475..801R) where the 12um faint galaxy counts are presented and analysed per galaxy type with the evolutionary code PEGASE.3.
23096. UMIST database. 1995
- ID:
- ivo://CDS.VizieR/J/A+AS/121/139
- Title:
- UMIST database. 1995
- Short Name:
- J/A+AS/121/139
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the release of a new version of the UMIST database for astrochemistry. The database contains the rate coefficients of 3864 gas-phase reactions important in interstellar and circumstellar chemistry and involves 395 species and 12 elements. The previous (1990, Millar et al. 1991A&AS...87..585M) version of this database has been widely used by modellers. In addition to the rate coefficients, we also tabulate permanent electric dipole moments of the neutral species and heats of formation. A numerical model of the chemical evolution of a dark cloud is calculated and important differences to that calculated with the previous database noted.
- ID:
- ivo://CDS.VizieR/J/A+A/538/A11
- Title:
- 70um-1.2mm and N_2_H+ maps of IRDC18454 (W43)
- Short Name:
- J/A+A/538/A11
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The earliest stages of high-mass star formation are still poorly characterized. Densities, temperatures and kinematics are crucial parameters for simulations of high-mass star formation. It is also unknown whether the initial conditions vary with environment. We want to investigate the youngest massive gas clumps in the environment of extremely active star formation. We selected the IRDC18454 complex, directly associated with the W43 Galactic mini-starburst, and observed it in the continuum emission between 70um and 1.2mm with Herschel, APEX and the 30m telescope, and in spectral line emission of N_2_H+ and ^13^CO with the Nobeyama 45m, the IRAM 30m and the Plateau de Bure Interferometer.
- ID:
- ivo://CDS.VizieR/J/ApJ/750/98
- Title:
- 24um observations of AFGKM stars of 3 clusters
- Short Name:
- J/ApJ/750/98
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use Spitzer Space Telescope 24 {mu}m data to search for debris disks among 122 AFGKM stars from the ~670 Myr clusters Hyades, Coma Ber, and Praesepe, utilizing a number of advances in data reduction and determining the intrinsic colors of main-sequence stars. For our sample, the 1{sigma} dispersion about the main-sequence V-K_S_, K_S_-[24] locus is approximately 3.1%. We identify seven debris disks at 10% or more ( >=3{sigma} confidence level) above the expected K_S_-[24] for purely photospheric emission. The incidence of excesses of 10% or greater in our sample at this age is 5.7^+3.1^_-1.7_%. Combining with results from the literature, the rate is 7.8^+4.2^_-2.1_% for early-type (B9-F4) stars and 2.7^+3.3^_-1.7_% for solar-like (F5-K9) stars. Our primary sample has strict criteria for inclusion to allow comparison with other work; when we relax these criteria, three additional debris disks are detected. They are all around stars of solar-like type and hence reinforce our conclusion that disks around such stars are still relatively common at 670Myr and are similar to the rate around early-type stars. The apparently small difference in decay rates between early-type and solar-like stars is inconsistent with the first-order theoretical predictions that the later type stellar disks would decay an order of magnitude more quickly than the earlier type ones.
- ID:
- ivo://CDS.VizieR/J/A+AS/101/59
- Title:
- 1-20um observations of Herbig-Haro objects
- Short Name:
- J/A+AS/101/59
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- For 58 exciting sources of Herbig-Haro objects/jets (HHES) we present a catalogue of photometric data for the infrared spectral bands JHKLMNQ (1-20 um). This catalog is based on our own observations and published information available up to May 1992. For each source, these data are presented in chronological order. In addition to the broad-band data, narrow-band N(8-13 um) photometric data are also provided. The flux calibration for each observational equipment is explicitly noted as the diaphragm sizes are used. The same kind of information for the established members of the FU Ori class is complementing the HHES catalogue. The frequency of observations and the photometric quality of the catalogued data are shortly discussed.
- ID:
- ivo://CDS.VizieR/J/MNRAS/379/663
- Title:
- 850um observations of W3 giant molecular cloud
- Short Name:
- J/MNRAS/379/663
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have surveyed a ~0.9 square degree area of the W3 giant molecular cloud (GMC) and star-forming region in the 850-um continuum, using the Submillimetre Common-User Bolometer Array on the James Clerk Maxwell Telescope. A complete sample of 316 dense clumps were detected with a mass range from around 13 to 2500M_{sun}_.