Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/417/2230
- Title:
- BVRI+SDSS+2MASS and WISE photometry of 289 stars
- Short Name:
- J/MNRAS/417/2230
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present colour transformations for the conversion of the W1 and W2 magnitudes of the Wide-field Infrared Survey Explorer (WISE) photometric system to the Johnson-Cousins BVRI, Sloan Digital Sky Survey gri and Two-Micron All-Sky Survey JHKs photometric systems, for dwarfs.
- ID:
- ivo://CDS.VizieR/J/A+A/608/L8
- Title:
- Calibration of G passband for Gaia DR1
- Short Name:
- J/A+A/608/L8
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- On September 2016 the first data from Gaia were released (DR1). The first release included photometry for over 109 sources in the very broad G system. To test the correspondence between G magnitudes in DR1 and the synthetic equivalents derived using spectral energy distributions from observed and model spectrophotometry. To correct the G passband curve and to measure the zero point in the Vega system. Methods. I have computed the synthetic G and Tycho-2 BTVT photometry for a sample of stars using the Next Generation Spectral Library (NGSL) and the Hubble Space Telescope (HST) CALSPEC spectroscopic standards. I have found that the nominal G passband curve is too blue for the DR1 photometry, as shown by the presence of a color with an exponent of 0.783 eliminates the color term. The corrected passband has a Vega zero point of 0.070+/-0.004 magnitudes.
- ID:
- ivo://CDS.VizieR/J/MNRAS/440/1080
- Title:
- Calibration of H{alpha} fluxes in SHS
- Short Name:
- J/MNRAS/440/1080
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The AAO/UKST SuperCOSMOS H{alpha} Survey (SHS) was, when completed in 2003, a powerful addition to extant wide-field surveys. The combination of areal coverage, spatial resolution and sensitivity in a narrow imaging band, still marks it out today as an excellent resource for the astronomical community. The 233 separate fields are available online in digital form, with each field covering 25deg^2^. The SHS has been the motivation for equivalent surveys in the north, and new digital H{alpha} surveys now beginning in the south such as VPHAS+. It has been the foundation of many important discovery projects with the Macquarie/AAO/Strasbourg H{alpha} planetary nebula project being a particularly successful example. However, the full potential of the SHS has been hampered by lack of a clear route to acceptable flux calibration from the base photographic data. We have determined the calibration factors for 170 individual SHS fields, and present a direct pathway to the measurement of integrated H{alpha} fluxes and surface brightnesses for resolved nebulae detected in the SHS. We also include a catalogue of integrated H{alpha} fluxes for >100 planetary and other nebulae measured from the SHS, and use these data to show that fluxes, accurate to +/-0.10-0.14dex (~25-35%), can be obtained from these fields. For the remaining 63 fields, a mean calibration factor of 12.0 counts/pixel/R can be used, allowing the determination of reasonable integrated fluxes accurate to better than +/-0.2dex (~50%). We outline the procedures involved and the caveats that need to be appreciated in achieving such flux measurements. This paper forms a handy reference source that will significantly increase the scientific utility of the SHS.
245. CALIFA DR2
- ID:
- ivo://CDS.VizieR/J/A+A/576/A135
- Title:
- CALIFA DR2
- Short Name:
- J/A+A/576/A135
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper describes the Second Public Data Release (DR2) of the Calar Alto Legacy Integral Field Area (CALIFA) survey. The data for 200 objects are made public, including the 100 galaxies of the First Public Data Release (DR1). Data were obtained with the integral-field spectrograph PMAS/PPak mounted on the 3.5m telescope at the Calar Alto observatory. Two different spectral setups are available for each galaxy, (i) a low-resolution V500 setup covering the wavelength range 3745-7500{AA} with a spectral resolution of 6.0{AA} (FWHM); and (ii) a medium-resolution V1200 setup covering the wavelength range 3650-4840{AA} with a spectral resolution of 2.3{AA} (FWHM). The sample covers a redshift range between 0.005 and 0.03, with a wide range of properties in the color-magnitude diagram, stellar mass, ionization conditions, and morphological types. All the cubes in the data release were reduced with the latest pipeline, which includes improved spectrophotometric calibration, spatial registration, and spatial resolution. The spectrophotometric calibration is better than 6% and the median spatial resolution is 2.4". In total, the second data release contains over 1.5 million spectra.
- ID:
- ivo://CDS.VizieR/J/A+A/595/A62
- Title:
- CALIFA galaxies O/H and N/O slopes
- Short Name:
- J/A+A/595/A62
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The study of the integrated properties of star-forming galaxies is central to understand their formation and evolution. Some of these properties are extensive and therefore their analysis require totally covering and spatially resolved observations. Among these properties, metallicity can be defined in spiral discs by means of integral field spectroscopy (IFS) of individual HII regions. The simultaneous analysis of the abundances of primary elements, as oxygen, and secondary, as nitrogen, also provides clues about the star formation history and the processes that shape the build-up of spiral discs. Our main aim is to analyse simultaneously O/H and N/O abundance ratios in HII regions in different radial positions of the discs in a large sample of spiral galaxies to obtain the slopes and the characteristic abundance ratios that can be related to their integrated properties. We analysed the optical spectra of individual selected HII regions extracted from a sample of 350 spiral galaxies of the CALIFA survey. We calculated total O/H abundances and, for the first time, N/O ratios using the semi-empirical routine HII-CHI-MISTRY, which, according to Perez-Montero (2014MNRAS.441.2663P), is consistent with the direct method and reduces the uncertainty in the O/H derivation using [NII] lines owing to the dispersion in the O/H-N/O relation. Then we performed linear fittings to the abundances as a function of the de-projected galactocentric distances.
- ID:
- ivo://CDS.VizieR/J/A+A/593/A114
- Title:
- CALIFA space density distribution of galaxies
- Short Name:
- J/A+A/593/A114
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We measure the distribution in absolute magnitude-circular velocity space for a well-defined sample of 199 rotating Calar Alto Legacy Integral Field Area Survey (CALIFA) galaxies using their stellar kinematics. Our aim in this analysis is to avoid subjective selection criteria and to take volume and large-scale structure factors into account. Using stellar velocity fields instead of gas emission line kinematics allows including rapidly rotating early type galaxies. Our initial sample contains 277 galaxies with available stellar velocity fields and growth curve r-band photometry. After rejecting 51 velocity fields that could not be modelled due to the low number of bins, foreground contamination or significant interaction we perform Markov Chain Monte Carlo (MCMC) modelling of the velocity fields, obtaining the rotation curve and kinematic parameters and their realistic uncertainties. We perform an extinction correction and calculate the circular velocity v_circ_ accounting for pressure support a given galaxy has. The resulting galaxy distribution on the M_r_-v_circ_ plane is then modelled as a mixture of two distinct populations, allowing robust a nd reproducible rejection of outliers, a significant fraction of which are slow rotators. The selection effects are understood well enough that the incompleteness of thesample can be corrected for and the 199 galaxies can be weighted by volume and large-scale structure factors enabling us to fit a volume-corrected Tully-Fisher relation (TFR). More importantly, we also provide the volume-corrected distribution of galaxies in the M_r_-v_circ_ plane, which can be compared with cosmological simulations. The joint distribution of the luminosity and circular velocity space densities, representative over the range of -20>M_r_>-22mag, can place more stringent constraints on the galaxy formation and evolution scenarios than linear TFR fit parameters or the luminosity function alone.
- ID:
- ivo://CDS.VizieR/J/AJ/155/89
- Title:
- California-Kepler Survey (CKS). IV. Planets
- Short Name:
- J/AJ/155/89
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Probing the connection between a star's metallicity and the presence and properties of any associated planets offers an observational link between conditions during the epoch of planet formation and mature planetary systems. We explore this connection by analyzing the metallicities of Kepler target stars and the subset of stars found to host transiting planets. After correcting for survey incompleteness, we measure planet occurrence: the number of planets per 100 stars with a given metallicity M. Planet occurrence correlates with metallicity for some, but not all, planet sizes and orbital periods. For warm super-Earths having P=10-100 days and R_P_=1.0-1.7 R_{Earth}_, planet occurrence is nearly constant over metallicities spanning -0.4 to +0.4 dex. We find 20 warm super-Earths per 100 stars, regardless of metallicity. In contrast, the occurrence of warm sub-Neptunes (R_P_=1.7-4.0 R_{Earth}_) doubles over that same metallicity interval, from 20 to 40 planets per 100 stars. We model the distribution of planets as df{prop.to}10^{beta}M^dM, where {beta} characterizes the strength of any metallicity correlation. This correlation steepens with decreasing orbital period and increasing planet size. For warm super-Earths {beta}=-0.3_-0.2_^+0.2^, while for hot Jupiters {beta}=+3.4_-0.8_^+0.9^. High metallicities in protoplanetary disks may increase the mass of the largest rocky cores or the speed at which they are assembled, enhancing the production of planets larger than 1.7 R_{Earth}_. The association between high metallicity and short-period planets may reflect disk density profiles that facilitate the inward migration of solids or higher rates of planet-planet scattering.
- ID:
- ivo://CDS.VizieR/J/AJ/155/48
- Title:
- California-Kepler Survey (CKS). V. Masses and radii
- Short Name:
- J/AJ/155/48
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have established precise planet radii, semimajor axes, incident stellar fluxes, and stellar masses for 909 planets in 355 multi-planet systems discovered by Kepler. In this sample, we find that planets within a single multi-planet system have correlated sizes: each planet is more likely to be the size of its neighbor than a size drawn at random from the distribution of observed planet sizes. In systems with three or more planets, the planets tend to have a regular spacing: the orbital period ratios of adjacent pairs of planets are correlated. Furthermore, the orbital period ratios are smaller in systems with smaller planets, suggesting that the patterns in planet sizes and spacing are linked through formation and/or subsequent orbital dynamics. Yet, we find that essentially no planets have orbital period ratios smaller than 1.2, regardless of planet size. Using empirical mass-radius relationships, we estimate the mutual Hill separations of planet pairs. We find that 93% of the planet pairs are at least 10 mutual Hill radii apart, and that a spacing of ~20 mutual Hill radii is most common. We also find that when comparing planet sizes, the outer planet is larger in 65%+/-0.4% of cases, and the typical ratio of the outer to inner planet size is positively correlated with the temperature difference between the planets. This could be the result of photo-evaporation.
- ID:
- ivo://CDS.VizieR/J/ApJ/823/95
- Title:
- CANDELS GOODS-S sources Chandra counterparts
- Short Name:
- J/ApJ/823/95
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Improving the capabilities of detecting faint X-ray sources is fundamental to increase the statistics on faint high-z AGN and star-forming galaxies. We performed a simultaneous Maximum Likelihood PSF fit in the [0.5-2]keV and [2-7]keV energy bands of the 4Ms Chandra Deep Field South (CDFS) data at the position of the 34930 CANDELS H-band selected galaxies. For each detected source we provide X-ray photometry and optical counterpart validation. We validated this technique by means of a raytracing simulation. We detected a total of 698 X-ray point-sources with a likelihood L>4.98 (i.e.> 2.7{sigma}). We show that the prior knowledge of a deep sample of Optical-NIR galaxies leads to a significant increase of the detection of faint (i.e. ~10^-17^cgs in the [0.5-2]keV band) sources with respect to "blind" X-ray detections. By including previous catalogs, this work increases the total number of X-ray sources detected in the 4Ms CDFS, CANDELS area to 793, which represents the largest sample of extremely faint X-ray sources assembled to date. Our results suggest that a large fraction of the optical counterparts of our X-ray sources determined by likelihood ratio actually coincides with the priors used for the source detection. Most of th e new detected sources are likely star-forming galaxies or faint absorbed AGN. We identified a few sources sources with putative photometric redshift z>4. Despite the low number statistics, this sample significantly increases the number of X-ray selected candidate high-z AGN.