- ID:
- ivo://CDS.VizieR/J/MNRAS/491/3496
- Title:
- Andromeda XIX member stars
- Short Name:
- J/MNRAS/491/3496
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- With a central surface brightness of {mu}_0_=29.3mag/arcsec^2^, and half-light radius of r_half_=3.1^+0.9^_-1.1_kpc, Andromeda XIX (And XIX) is an extremely diffuse satellite of Andromeda. We present spectra for ~100 red giant branch stars in this galaxy, plus 16 stars in a nearby stellar stream. With this exquisite data set, we re-derive the properties of And XIX, measuring a systemic velocity of <v_r_>=-109.0+/-1.6km/s and a velocity dispersion of {sigma}_vr_=7.8^+1.7^_-1.5_km/s (higher than derived in our previous work). We marginally detect a velocity gradient along the major axis of dv/dX=-2.1+/-1.8km/s/kpc. We find its mass-to-light ratio is higher than galaxies of comparable stellar mass ([M/L]_half_=278^+146^_-198_M_{sun}_/L_{sun}_), but its dynamics place it in a halo with a similar total mass to these galaxies. This could suggest that And XIX is a 'puffed up' dwarf galaxy, whose properties have been altered by tidal processes, similar to its Milky Way counterpart, Antlia II. For the nearby stream, we measure v_r_=-279.2+/-3.7km/s, and {sigma}_rv_=13.8^+3.5^_-2.6_km/s. We measure its metallicity, and find it to be more metal rich than And XIX, implying that the two features are unrelated. Finally, And XIX's dynamical and structural properties imply it is a local analogue to ultradiffuse galaxies (UDGs). Its complex dynamics suggest that the masses of distant UDGs measured from velocity dispersions alone should be carefully interpreted.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/440/942
- Title:
- 100 and 160um fluxes of nearby galaxies
- Short Name:
- J/MNRAS/440/942
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Herschel/PACS 100 and 160{mu}m integrated photometry for the 323 galaxies in the Herschel Reference Survey (HRS), a K-band, volume-limited sample of galaxies in the local Universe. Once combined with the Herschel/SPIRE observations already available, these data make the HRS the largest representative sample of nearby galaxies with homogeneous coverage across the 100-500{mu}m wavelength range. In this paper, we take advantage of this unique data set to investigate the properties and shape of the far-infrared/submillimetre spectral energy distribution in nearby galaxies. We show that, in the stellar mass range covered by the HRS (8<~log(M*/M_{sun}_)<~12), the far-infrared/submillimetre colours are inconsistent with a single modified blackbody having the same dust emissivity index {beta} for all galaxies. In particular, either {beta} decreases or multiple temperature components are needed, when moving from metal-rich/gas-poor to metal-poor/gas-rich galaxies. We thus investigate how the dust temperature and mass obtained from a single modified blackbody depend on the assumptions made on {beta}. We show that, while the correlations between dust temperature, galaxy structure and star formation rate are strongly model dependent, the dust mass scaling relations are much more reliable, and variations of {beta} only change the strength of the observed trends.
- ID:
- ivo://CDS.VizieR/VIII/13
- Title:
- A new catalog of 53522 4.85GHz sources
- Short Name:
- VIII/13
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- of paper: A catalog of 53522 4.85GHz sources between 0 and 75 degrees declination has been generated from observations taken with the NRAO Green Blank 300foot (91m) telescope. The flux limit of the catalog is dependent on declination and ranges from about 40mJy at 0degree to 20mJy at 60degrees. The source positions given in the catalog have a 95% confidence radius of about 50arcsec. Spectral indices have been calculated for 29051 sources which have counterparts in the Texas 365MHz northern sky survey.
- ID:
- ivo://CDS.VizieR/J/AJ/142/139
- Title:
- A new catalog of HII regions in M31
- Short Name:
- J/AJ/142/139
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new catalog of HII regions in M31. The full disk of the galaxy (~24kpc from the galaxy center) is covered in a 2.2deg^2^ mosaic of 10 fields observed with the Mosaic Camera on the Mayall 4m telescope as part of the Local Group Galaxies survey.
- ID:
- ivo://CDS.VizieR/J/ApJS/231/20
- Title:
- A new 95GHz methanol maser catalog. I.
- Short Name:
- J/ApJS/231/20
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Purple Mountain Observatory 13.7m radio telescope has been used to search for 95GHz (8_0_-7_1_A^+^) class I methanol masers toward 1020 Bolocam Galactic Plane Survey (BGPS) sources, leading to 213 detections. We have compared the line width of the methanol and HCO^+^ thermal emission in all of the methanol detections, and on that basis, we find that 205 of the 213 detections are very likely to be masers. This corresponds to an overall detection rate of 95 GHz methanol masers toward our BGPS sample of 20%. Of the 205 detected masers, 144 (70%) are new discoveries. Combining our results with those of previous 95GHz methanol maser searches, a total of 481 95GHz methanol masers are now known. We have compiled a catalog listing the locations and properties of all known 95GHz methanol masers.
- ID:
- ivo://CDS.VizieR/J/AJ/158/22
- Title:
- A new IR study of intrinsic and extrinsic S-type stars
- Short Name:
- J/AJ/158/22
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We collect all known intrinsic and extrinsic S-type stars to discuss their infrared properties and find their difference in the infrared using photometric data from the Two Micron All Sky Survey, Wide Field Infrared Survey Explorer, and Infrared Astronomical Satellite missions. Then we look for the diagnosis to extract intrinsic S-type stars from the large unclassified sample. We found that, statistically, intrinsic S-type stars have larger infrared excesses than extrinsic S-type stars in the wavelength region of 1-60 {mu}m due to thicker dusty circumstellar envelopes. We also found that only intrinsic S-type stars occupy the reddest color areas in all of the two-color diagrams we presented. Finally, 172 new intrinsic S-type stars are presented in this paper. This makes the number of known intrinsic S-type stars almost double. In addition, some intrinsic and extrinsic S-type stars have power-law distributions in some two-color diagrams with the wavelength longer than 5 {mu}m. The possible reason for this is also discussed.
- ID:
- ivo://CDS.VizieR/III/166
- Title:
- A New Library of Optical Spectra
- Short Name:
- III/166
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Silva and Cornell have compiled a new digital optical stellar spectra library, consisting of intensities at 5A intervals between 3510A and 8930A for 72 different spectral types. These types range from O to M and luminosities range from I to V. Some weak-line and strong-line spectra are also included. The intensities are in ergs/A, normalized to 100 at 5450A.
- ID:
- ivo://CDS.VizieR/J/AJ/161/187
- Title:
- A new martian crater chronology
- Short Name:
- J/AJ/161/187
- Date:
- 16 Mar 2022 11:45:44
- Publisher:
- CDS
- Description:
- Crater chronologies are a fundamental tool to assess the relative and absolute ages of planetary surfaces when direct radiometric dating is not available. Martian crater chronologies are derived from lunar crater spatial densities on terrains with known radiometric ages, and thus they critically depend on the Moon-to-Mars extrapolation. This extrapolation requires knowledge of the time evolution of the impact flux, including contributions from various impactor populations, factors that are not trivially connected to the dynamical evolution of the early Solar System. In this paper, we will present a new Martian crater chronology based on current dynamical models, and consider the main sources of uncertainties (e.g., impactor size-frequency distribution; dynamical models with late and early instabilities, etc.). The resulting "envelope" of Martian crater chronologies significantly differs from previous chronologies. The new Martian crater chronology is discussed using two interesting applications: Jezero crater's dark terrain (relevant to the NASA Mars 2020 mission) and the southern heavily cratered highlands. Our results indicate that Jezero's dark terrain may have formed ~3.1Ga, i.e., up to 0.5Gyr older than previously thought. In addition, available crater chronologies (including our own) overestimate the number of craters larger than 150km on the southern highlands, suggesting either that large craters have been efficiently erased over Martian history or that dynamical models need further refinement. Further, our chronology constrains the age of Isidis basin to be 4.05-4.2Ga and that of the Borealis basin to be 4.35-4.40Ga; these are predictions that can be tested with future sample and return missions.
- ID:
- ivo://CDS.VizieR/J/AJ/154/269
- Title:
- A new photo-z method for quasars in Stripe 82
- Short Name:
- J/AJ/154/269
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new algorithm to estimate quasar photometric redshifts (photo-zs), by considering the asymmetries in the relative flux distributions of quasars. The relative flux models are built with multivariate Skew-t distributions in the multidimensional space of relative fluxes as a function of redshift and magnitude. For 151392 quasars in the SDSS, we achieve a photo-z accuracy, defined as the fraction of quasars with the difference between the photo-z z_p_ and the spectroscopic redshift z_s_, |{Delta}_z_|=|z_s_-z_p_|/(1+z_s_) within 0.1, of 74%. Combining the WISE W1 and W2 infrared data with the SDSS data, the photo-z accuracy is enhanced to 87%. Using the Pan-STARRS1 or DECaLS photometry with WISE W1 and W2 data, the photo-z accuracies are 79% and 72%, respectively. The prior probabilities as a function of magnitude for quasars, stars, and galaxies are calculated, respectively, based on (1) the quasar luminosity function, (2) the Milky Way synthetic simulation with the Besancon model, and (3) the Bayesian Galaxy Photometric Redshift estimation. The relative fluxes of stars are obtained with the Padova isochrones, and the relative fluxes of galaxies are modeled through galaxy templates. We test our classification method to select quasars using the DECaLS g, r, z, and WISE W1 and W2 photometry. The quasar selection completeness is higher than 70% for a wide redshift range 0.5<z<4.5, and a wide magnitude range 18<r<21.5 mag. Our photo-z regression and classification method has the potential to extend to future surveys. The photo-z code will be publicly available.
- ID:
- ivo://CDS.VizieR/J/ApJ/827/118
- Title:
- A new reverberation mapping campaign on NGC 5548
- Short Name:
- J/ApJ/827/118
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- NGC 5548 is the best-observed reverberation-mapped active galactic nucleus with long-term, intensive monitoring. Here we report results from a new observational campaign between 2015 January and July. We measure the centroid time lag of the broad H{beta} emission line with respect to the 5100{AA} continuum and obtain {tau}_cent_=7.20_-0.35_^+1.33^days in the rest frame. This yields a black hole mass of M.=8.71_-2.61_^+3.21^x10^7^M_{sun}_ using a broad H{beta} line dispersion of 3124+/-302km/s and a virial factor of f_BLR_=6.3+/-1.5 for the broad-line region (BLR), consistent with the mass measurements from previous H{beta} campaigns. The high-quality data allow us to construct a velocity-binned delay map for the broad H{beta} line, which shows a symmetric response pattern around the line center, a plausible kinematic signature of virialized motion of the BLR. Combining all the available measurements of H{beta} time lags and the associated mean 5100{AA} luminosities over 18 campaigns between 1989 and 2015, we find that the H{beta} BLR size varies with the mean optical luminosity, but, interestingly, with a possible delay of 2.35_-1.25_^+3.47^ years. This delay coincides with the typical BLR dynamical timescale of NGC 5548, indicating that the BLR undergoes dynamical changes, possibly driven by radiation pressure.
