- ID:
- ivo://CDS.VizieR/J/A+A/592/A48
- Title:
- Annotations to the second Planck cluster catalog
- Short Name:
- J/A+A/592/A48
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an all sky map of the y-type distortion calculated from the full mission Planck HFI (High Frequency Instrument) data using the recently proposed approach to component separation based on parametric model fitting and model selection. This simple model selection approach allows us to distinguish between carbon monoxide (CO) line emission and y-type distortion, something that is not possible using the internal linear combination based methods. We create a mask to cover the regions of significant CO emission relying on the information in the {chi}^2^ map obtained when fitting for the y-distortion and CO emission to the lowest four HFI channels. We revisit the second Planck cluster catalog and try to quantify the quality of the cluster candidates in an approach that is similar in spirit to Aghanim et al. (2015A&A...580A.138A). We find that at least 93% of the clusters in the cosmology sample are free of CO contamination. We also find that 59% of unconfirmed candidates may have significant contamination from molecular clouds. We agree with Planck Collaboration et al. (2016, A&A, in press., arXiv:1502.01598) for the worst offenders. We suggest an alternative validation strategy of measuring and subtracting the CO emission from the Planck cluster candidates using radio telescopes thus improving the reliability of the catalog. Our CO mask and annotations to the Planck cluster catalog identifying cluster candidates with possible CO contamination are made publicly available.
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- ID:
- ivo://CDS.VizieR/J/A+A/626/A69
- Title:
- An old nova remnant in M22
- Short Name:
- J/A+A/626/A69
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A nova is a cataclysmic event on the surface of a white dwarf in a binary system that increases the overall brightness by several orders of magnitude. Although binary systems with a white dwarf are expected to be overabundant in globular clusters (GCs) compared to the Galaxy, only two novae from Galactic globular clusters have been observed. We present the discovery of an emission nebula in the Galactic globular cluster M 22 (NGC 6656) in observations made with the integral-field spectrograph MUSE. We extract the spectrum of the nebula and use the radial velocity determined from the emission lines to confirm that the nebula is part of NGC 6656. Emission-line ratios are used to determine the electron temperature and density. It is estimated to have a mass of 1 to 17x10^-5^ solar masses. This mass and the emission-line ratios indicate that the nebula is a nova remnant. Its position coincides with the reported location of a 'guest star', an ancient Chinese term for transients, observed in May 48 BCE. With this discovery, this nova may be one of the oldest confirmed extrasolar events recorded in human history.
- ID:
- ivo://CDS.VizieR/J/A+A/615/A42
- Title:
- Anomalous extinction sightlines stars polarisation
- Short Name:
- J/A+A/615/A42
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Highly reddened type Ia supernovae (SNe Ia) with low total-to-selective visual extinction ratio values, RV, also show peculiar linear polarization wavelength dependencies with peak polarizations at short wavelengths ({lambda}_max_<~0.4um). It is not clear why sightlines to SNe Ia display such different continuum polarization profiles from interstellar sightlines in the Milky Way with similar RV values. We investigate polarization profiles of a sample of Galactic stars with low RV values, along anomalous extinction sightlines, with the aim to find similarities to the polarization profiles that we observe in SN Ia sightlines. We undertook spectropolarimetry of 14 stars, used archival data for 3 additional stars, and ran dust extinction and polarization simulations (by adopting the picket-fence alignment model) to infer a simple dust model (size distribution, alignment) that can reproduce the observed extinction and polarization curves. Our sample of Galactic stars with low RV values and anomalous extinction sightlines displays normal polarization profiles with an average {lambda}_max_~0.53um, and is consistent within 3{sigma} to a larger coherent sample of Galactic stars from the literature. Despite the low RV values of dust toward the stars in our sample, the polarization curves do not show any similarity to the continuum polarization curves observed toward SNe Ia with low RV values. There is a correlation between the best-fit Serkowski parameters K and {lambda}_max_, but we did not find any significant correlation between RV and {lambda}_max_. Our simulations show that the K-{lambda}_max_ relationship is an intrinsic property of polarization. Furthermore, we have shown that in order to reproduce polarization curves with normal {lambda}_max_ and low RV values, a population of large (a >=0.1um) interstellar silicate grains must be contained in the dust composition.
- ID:
- ivo://CDS.VizieR/J/A+A/565/A103
- Title:
- Anomalous microwave emission in Galactic clouds
- Short Name:
- J/A+A/565/A103
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Anomalous microwave emission (AME) is believed to be due to electric dipole radiation from small spinning dust grains. The aim of this paper is a statistical study of the basic properties of AME regions and the environment in which they emit. We used WMAP and Planck maps, combined with ancillary radio and IR data, to construct a sample of 98 candidate AME sources, assembling SEDs for each source using aperture photometry on 1{deg}-smoothed maps from 0.408GHz up to 3000GHz. Each spectrum is fitted with a simple model of free-free, synchrotron (where necessary), cosmic microwave background (CMB), thermal dust, and spinning dust components. We find that 42 of the 98 sources have significant (>5{sigma}) excess emission at frequencies between 20 and 60GHz. An analysis of the potential contribution of optically thick free-free emission from ultra-compact HII regions, using IR colour criteria, reduces the significant AME sample to 27 regions. The spectrum of the AME is consistent with model spectra of spinning dust. Peak frequencies are in the range 20-35GHz except for the California nebula (NGC1499), which appears to have a high spinning dust peak frequency of (50+/-17)GHz. The AME regions tend to be more spatially extended than regions with little or no AME. The AME intensity is strongly correlated with the sub-millimetre/IR flux densities and comparable to previous AME detections in the literature. AME emissivity, defined as the ratio of AME to dust optical depth, varies by an order of magnitude for the AME regions. The AME regions tend to be associated with cooler dust in the range 14-20K and an average emissivity index, {beta}_d_, of +1.8, while the non-AME regions are typically warmer, at 20-27K. In agreement with previous studies, the AME emissivity appears to decrease with increasing column density. This supports the idea of AME originating from small grains that are known to be depleted in dense regions, probably due to coagulation onto larger grains. We also find a correlation between the AME emissivity (and to a lesser degree the spinning dust peak frequency) and the intensity of the interstellar radiation field, G_0_. Modelling of this trend suggests that both radiative and collisional excitation are important for the spinning dust emission. The most significant AME regions tend to have relatively less ionized gas (free-free emission), although this could be a selection effect. The infrared excess, a measure of the heating of dust associated with HII regions, is typically >4 for AME sources, indicating that the dust is not primarily heated by hot OB stars. The AME regions are associated with known dark nebulae and have higher 12{mu}m/25{mu}m ratios. The emerging picture is that the bulk of the AME is coming from the polycyclic aromatic hydrocarbons and small dust grains from the colder neutral interstellar medium phase.
- ID:
- ivo://CDS.VizieR/J/MNRAS/463/1332
- Title:
- Anomalous RRd stars in Magellanic Clouds
- Short Name:
- J/MNRAS/463/1332
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of a new subclass of double-mode RR Lyrae stars in the Large and Small Magellanic Clouds. The sample of 22 pulsating stars has been extracted from the latest edition of the Optical Gravitational Lensing Experiment collection of RR Lyrae variables in the Magellanic System. The stars pulsating simultaneously in the fundamental (F) and first-overtone (1O) modes have distinctly different properties than regular double-mode RR Lyrae variables (RRd stars). The P_1O_/P_F_ period ratios of our anomalous RRd stars are within a range of 0.725-0.738, while 'classical' double-mode RR Lyrae variables have period ratios in the range of 0.742-0.748. In contrast to the typical RRd stars, in the majority of the anomalous pulsators, the F-mode amplitudes are higher than the 1O-mode amplitudes. The light curves associated with the F-mode in the anomalous RRd stars show different morphology than the light curves of, both, regular RRd stars and single-mode RRab stars. Most of the anomalous double-mode stars show long-term modulations of the amplitudes (Blazhko-like effect). Translating the period ratios into the abundance parameter, Z, we find for our stars Z{in}(0.002, 0.005) - an order of magnitude higher values than typical for RR Lyrae stars. The mass range of the RRd stars inferred from the W_I_ versus P_F_ diagram is (0.55-0.75)M_{sun}_. These parameters cannot be accounted for with single star evolution assuming a Reimers-like mass-loss. Much greater mass-loss caused by interaction with other stars is postulated. We blame the peculiar pulsation properties of our stars to the parametric resonance instability of the 1O-mode to excitation of the F- and 2O-modes as with the inferred parameters of the stars 2{omega}_1O_~={omega}_F_+{omega}_2O_.
- ID:
- ivo://CDS.VizieR/J/MNRAS/437/3883
- Title:
- A non-parametric method for galaxy morphology
- Short Name:
- J/MNRAS/437/3883
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a non-parametric cell-based method of selecting highly pure and largely complete samples of spiral galaxies using photometric and structural parameters as provided by standard photometric pipelines and simple shape fitting algorithms. The performance of the method is quantified for different parameter combinations, using purely human-based classifications as a benchmark. The discretization of the parameter space allows a markedly superior selection than commonly used proxies relying on a fixed curve or surface of separation. Moreover, we find structural parameters derived using passbands longwards of the g band and linked to older stellar populations, especially the stellar mass surface density mu_*_ and the r band effective radius r_e_, to perform at least equally well as parameters more traditionally linked to the identification of spirals by means of their young stellar populations, e.g. UV/optical colours. In particular the distinct bimodality in the parameter mu_*_, consistent with expectations of different evolutionary paths for spirals and ellipticals, represents an often overlooked yet powerful parameter in differentiating between spiral and non-spiral/elliptical galaxies. We use the cell-based method for the optical parameter set including r_e_ in combination with the Sersic index n and the i-band magnitude to investigate the intrinsic specific star-formation rate - stellar mass relation ({psi}_*_-M_*_) for a morphologically defined volume limited sample of local universe spiral galaxies. The relation is found to be well described by {psi}_*_{propto}M_*_^-0.5^ over the range of 10^9.5^M_{sun}_<=M_*_<=10^11^M_{sun}_ with a mean interquartile range of 0.4dex. This is somewhat steeper than previous determinations based on colour-selected samples of star-forming galaxies, primarily due to the inclusion in the sample of red quiescent disks.
- ID:
- ivo://CDS.VizieR/VIII/3
- Title:
- An Optical Catalogue of Radio Galaxies
- Short Name:
- VIII/3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog contains basic optical information on all known radio galaxies (with L[radio] greater than about 10**[41] ergs/s) that had been identified as of 1979 and for which measured redshifts were available. The data include the right ascension and declination (1950); galaxy (optical) type; visual magnitude; photoelectric colors; redshift (z) and the spectral lines on which the redshift measurements were based; coordinate designations; radio flux and frequency; radio spectral index; other names; and the references for the galaxy identification, photometric data, redshift, radio flux, radio spectral index, and radio map number. Note that the ADC version of this catalog differs somewhat from the original printed catalog in that some fields were added or modified and other fields reordered. In addition to the catalog data file itself, two additional files containing the list of references for the catalog are also available. The first reference list is in alphabetical order, and the second is in numerical order.
- ID:
- ivo://CDS.VizieR/J/AJ/161/196
- Title:
- An optical overview of blazars with LAMOST. I.
- Short Name:
- J/AJ/161/196
- Date:
- 16 Mar 2022 11:51:00
- Publisher:
- CDS
- Description:
- The extragalactic {gamma}-rays sky observed by the Fermi Large Area Telescope (LAT) is dominated by blazars. In the fourth release of the Fermi LAT Point Source Catalog (4FGL) are sources showing a multifrequency behavior similar to that of blazars but lacking an optical spectroscopic confirmation of their nature, known as blazar candidates of uncertain type (BCUs). We aim at confirming the blazar nature of BCUs and test if new optical spectroscopic observations can reveal spectral features, allowing us to get a redshift estimate for known BL Lac objects. We also aim to search for and discover changing-look blazars (i.e., blazars that show a different classification at different epochs). We carry out an extensive search for optical spectra available in the Large Sky Area Multi-object Fibre Spectroscopic Telescope (LAMOST) Data Release 5 (DR5) archive. We select sources out of the 4FGL catalog, the list of targets from our follow-up spectroscopic campaign of unidentified or unassociated {gamma}-ray sources, and the multifrequency catalog of blazars: the Roma-BZCAT. We select a total of 392 spectra. We also compare some of the LAMOST spectra with those available in the literature. We classify 20 BCUs confirming their blazar-like nature. Then we obtain 15 new redshift estimates for known blazars. We discover 26 transitional (i.e., changing-look) blazars that changed their classification. Finally, we are able to confirm the blazar-like nature of six BL Lac candidates. All remaining sources analyzed agree with previous classifications. BL Lac objects are certainly the most elusive type of blazars in the {gamma}-ray extragalactic sky.
- ID:
- ivo://nasa.heasarc/ansuvpscat
- Title:
- ANS Ultraviolet Photometry Catalog of Point Sources
- Short Name:
- ANSUVPSCAT
- Date:
- 14 Feb 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- All reliable observations of point sources with the ultraviolet photometer onboard the Astronomical Netherlands Satellite (ANS) operating between the October 1974 and April 1976 are presented. Extended objects, non-detected objects, and objects at the edges of the instrument's field of view have been omitted. The catalog contains 3573 objects, mostly stars (the total ANS UV database contained 4800 observed positions). The ANS satellite observed in five UV channels centered around 150, 180, 220, 250 and 330 nm (1500, 1800, 2200, 2500 and 3300 Angstroms). The characteristics of the ANS UV photometric bands are: <pre> Band designation 15N 15W 18 22 25 33 ------------------------------------------------------------------------- Central wavelength (nm) 154.5 154.9 179.9 220.0 249.3 329.4 Bandwidth (nm) 5.0 14.9 14.9 20.0 15.0 10.1 </pre> The reported magnitudes were obtained from mean count rates converted to fluxes using the ANS absolute calibration of Wesselius et al. (1980A&A....85..221W). In addition to the ultraviolet magnitudes, the catalog contains positions taken from the satellite pointing, spectral types, and UBV data from other sources as well as comments on duplicity, variability, and miscellaneous notes concerning individual objects. Within the ANS photometric system, the UV magnitudes of different objects are comparable down to a level of 0.5-1.0%. Several studies on the intercomparison of all ANS data, and on the comparison of the ANS data with stellar models, with other UV satellites, and with the expected UV fluxes on the basis of ground-based information alone suggest that the ANS photometric system is well-established, and has, in particular, a linear dynamic range of at least a factor of 20,000. In these two respects, repeatability and dynamic range, the ANS UV instrument far exceeded all other UV missions then extant, e.g., TD-S2/68, OAO-WEP, and IUE. Of course, ANS had a much poorer spectral resolution, about 15 nm (150 Angstroms), than the other instruments. This table was created by the HEASARC in September 2011 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/II/97">CDS Catalog II/97</a> file ans.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://CDS.VizieR/II/97
- Title:
- ANS UV Catalogue of Point Sources
- Short Name:
- II/97
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog is a result of the observations made with the Astronomical Netherlands Satellite (ANS) which operated between October 1974 and April 1976. The ANS satellite observed in five UV channels centered around 150, 180, 220, 250 and 330nm. The photometric bands are: -------------------------------------------------------------------------- Band designation 15N 15W 18 22 25 33 -------------------------------------------------------------------------- Central wavelength (nm) 154.5 154.9 179.9 220.0 249.3 329.4 Bandwidth (nm) 5.0 14.9 14.9 20.0 15.0 10.1 -------------------------------------------------------------------------- The reported magnitudes were obtained from mean count rates converted to fluxes using the ANS absolute calibration of Wesselius et al. (1980A&A....85..221W). In addition to the ultraviolet magnitudes, the catalog contains positions taken from the satellite pointing, spectral types, and UBV data from other sources as well as comments on duplicity, variability, and miscellaneous notes concerning individual objects.
