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- ID:
- ivo://CDS.VizieR/J/A+A/621/A133
- Title:
- ABYSS HUDF WFC3 IR mosaics
- Short Name:
- J/A+A/621/A133
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Hubble Ultra Deep field (HUDF) is the deepest region ever observed with the Hubble Space Telescope. With the main objective of unveiling the nature of galaxies up to z~7-8, the observing and reduction strategy have focused on the properties of small and unresolved objects, rather than the outskirts of the largest objects, which are usually over-subtracted. We aim to create a new set of WFC3 IR mosaics of the HUDF using novel techniques to preserve the properties of the low surface brightness regions. We created ABYSS a pipeline that optimises the estimate and modelling of low-level systematic effects to obtain a robust background subtraction. We have improved four key points in the reduction: 1) creation of new absolute sky flat fields, 2) extended persistence models, 3) dedicated sky background subtraction and 4) robust co-adding. The new mosaics successfully recover the low surface brightness structure removed on the previous HUDF published reductions. The amount of light recovered with a mean surface brightness dimmer than mu=26mag/arcsec^2^ is equivalent to a m=19 mag source when compared to the XDF and a m=20mag compared to the HUDF12. We present a set of techniques to reduce ultra-deep images (mu>32.5mag/arcsec^2^, 3 sigma in 10x10 arcsec boxes), that successfully allow to detect the low surface brightness structure of extended sources on ultra deep surveys. The developed procedures are applicable to HST, JWST, EUCLID and many other space and ground-based observatories. We made the final ABYSS WFC3 IR HUDF mosaics publicly available at http://www.iac.es/proyecto/abyss/.
- ID:
- ivo://CDS.VizieR/B/assocdata
- Title:
- Associated data in VizieR
- Short Name:
- B/assocdata
- Date:
- 20 Mar 2022 05:13:55
- Publisher:
- CDS
- Description:
- The ObsCore VizieR table gather FITS images, spectra and time-series into a single table. The contents are the VizieR associated data, publilished in original article with the tables. The metadata comes from the ObsCore Data Model. ObsCore (Tody et al. 2011) is a standard of the Virtual Observatory used to map images,spectra or time-series resources with standardized metadata.
- ID:
- ivo://CDS.VizieR/J/A+A/643/A110
- Title:
- beta Cas BRITE and SMEI light curves
- Short Name:
- J/A+A/643/A110
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- F type stars are characterised by several physical processes such as different pulsation mechanisms, rotation, convection, diffusion, and magnetic fields. The rapidly rotating delta Scuti star beta Cas can be considered as a benchmark star to study the interaction of several of these effects. We investigate the pulsational and magnetic field properties of beta Cas. We also determine the star's apparent fundamental parameters and chemical abundances. Based on photometric time series obtained from three different space missions (BRITE-Constellation, SMEI, and TESS), we conduct a frequency analysis and investigate the stability of the pulsation amplitudes over four years of observations. We investigate the presence of a magnetic field and its properties using spectropolarimetric observations taken with the Narval instrument by applying the Least Square Deconvolution and Zeeman Doppler Imaging techniques. beta Cas shows only three independent p-mode frequencies down to the few ppm-level; its highest amplitude frequency is suggested to be a n=3, l=2, m=0 mode. Its magnetic field structure is quite complex and almost certainly of a dynamo origin. beta Cas' atmosphere is slightly deficient in iron peak elements and slightly overabundant in C, O, and heavier elements. Atypically for delta Scuti stars, we can only detect three pulsation modes down to exceptionally low noise levels for beta Cas.The star is also one of very few delta Scuti pulsators known to date to show a measurable magnetic field, and the first delta Scuti star with a dynamo magnetic field. These characteristics make beta Cas an interesting target for future studies of dynamo processes in the thin convective envelopes of F-type stars, of the transition region between fossil and dynamo fields, and the interaction between pulsations and magnetic field.
- ID:
- ivo://CDS.VizieR/J/A+A/627/A28
- Title:
- beta Pic BRITE, bRing, SMEI light curves
- Short Name:
- J/A+A/627/A28
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Exoplanet properties crucially depend on the parameters of their host stars: more accurate stellar parameters yield more accurate exoplanet characteristics. When the exoplanet host star shows pulsations, asteroseismology can be used for an improved description of the stellar parameters. We aim to revisit the pulsational properties of {beta} Pic and identify its pulsation modes from normalized amplitudes in five different passbands. We also investigate the potential presence of a magnetic field. We conducted a frequency analysis using three seasons of BRITE-Constellation observations in the two BRITE filters, the about 620-day-long bRing light curve, and the nearly 8-year-long SMEI photometric time series. We calculated normalized amplitudes using all passbands and including previously published values obtained from ASTEP observations. We investigated the magnetic properties of {beta} Pic using spectropolarimetric observations conducted with the HARPSpol instrument. Using 2D rotating models, we fit the normalized amplitudes and frequencies through Monte Carlo Markov chains. We identify 15 pulsation frequencies in the range from 34 to 55d^-1^, where two, F13 at 53.6917d^-1^ and F11 at 50.4921d^-1^, display clear amplitude variability. We use the normalized amplitudes in up to five passbands to identify the modes as three l=1, six l=2, and six l=3 modes. {beta} Pic is shown to be non-magnetic with an upper limit of the possible undetected dipolar field of 300 Gauss. Multiple fits to the frequencies and normalized amplitudes are obtained, including one with a near equator-on inclination for {beta} Pic, which corresponds to our expectations based on the orbital inclination of {beta} Pic b and the orientation of the circumstellar disk. This solution leads to a rotation rate of 27% of the Keplerian breakup velocity, a radius of 1.497+/-0.025R_{sun}_, and a mass of 1.797+/-0.035M_{sun}_. The ~2% errors in radius and mass do not account for uncertainties in the models and a potentially erroneous mode-identification.
- ID:
- ivo://CDS.VizieR/J/A+A/610/A30
- Title:
- B stars in 4 open clusters
- Short Name:
- J/A+A/610/A30
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Stellar physical properties of star clusters are poorly known and the cluster parameters are often very uncertain. Our goals are to perform a spectrophotometric study of the B star population in open clusters to derive accurate stellar parameters, search for the presence of circumstellar envelopes, and discuss the characteristics of these stars. The BCD spectrophotometric system is a powerful method to obtain stellar fundamental parameters from direct measurements of the Balmer discontinuity. To this end, we wrote the interactive code MIDE3700. The BCD parameters can also be used to infer the main properties of open clusters: distance modulus, color excess, and age. Furthermore, we inspected the Balmer discontinuity to provide evidence for the presence of circumstellar disks and identify Be star candidates. We used an additional set of high-resolution spectra in the H{alpha} region to confirm the Be nature of these stars. We provide Teff, logg, Mv, Mbol, and spectral types for a sample of 68 stars in the field of the open clusters NGC6087, NGC6250, NGC6383, and NGC6530, as well as the cluster distances, ages, and reddening. Then, based on a sample of 230 B stars in the direction of the 11 open clusters studied along this series of three papers, we report 6 new Be stars, 4 blue straggler candidates, and 15 B-type stars (called Bdd) with a double Balmer discontinuity, which indicates the presence of circumstellar envelopes. We discuss the distribution of the fraction of B, Be, and Bdd star cluster members per spectral subtype. The majority of the Be stars are dwarfs and present a maximum at the spectral type B2-B4 in young and intermediate-age open clusters (<40Myr). Another maximum of Be stars is observed at the spectral type B6-B8 in open clusters older than 40Myr, where the population of Bdd stars also becomes relevant. The Bdd stars seem to be in a passive emission phase. Our results support previous statements that the Be phenomenon is present along the whole main sequence band and occurs in very different evolutionary states.We find clear evidence of an increase of stars with circumstellar envelopes with cluster age. The Be phenomenon reaches its maximum in clusters of intermediate age (10-40Myr) and the number of B stars with circumstellar envelopes (Be plus Bdd stars) is also high for the older clusters (40-100Myr).
- ID:
- ivo://CDS.VizieR/B/corot
- Title:
- CoRoT observation log (N2-4.4)
- Short Name:
- B/corot
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CoRoT, a space astronomy mission, has measured photometric micro-variability of stars from minutes to months (up to 150 days) with a high duty cycle (more than 90%). The mission was led by CNES in association with four French laboratories and 7 participating countries and agencies (Austria, Belgium, Brazil, Germany, Spain, and the ESA Science Programme). The satellite was composed of a PROTEUS platform (the 3rd in the series) and a unique instrument: a stellar rapid photometer. It was launched on December 27th 2006 by a Soyuz Rocket, from Baikonour. The mission has lasted almost 6 years (the nominal 3-year duration and a 3-year extension) and has observed more than 160 000 stars. It stopped sending data on November 2nd 2012. Two regions of the sky were accessible for long period of time: circles of 10 degrees centered on the equator around alpha=06:50 and alpha=18:50. They were called the CoRoT eyes: the "anticenter" and the "center eye" (as they are approximately in these directions). Each pointing covers 1.4x2.8 square degrees within one of those CoRoT eyes. The original scientific objectives were focussed on the study of stellar pulsations (asteroseismology) to probe the internal structure of stars, and the detection of small exoplanets through their "transit" in front of their host star, and the measurement of their size. This lead to introduce two modes of observations, working simultaneously: - The "bright star" mode dedicated to very precise seismology of a small sample of bright and closeby stars - The "faint star" mode, observing a very large number of stars at the same time, to detect transits, which are rare events, as they imply the alignment of the star, the planet and the observer. The large amount of data gathered in this mode turned out to be extremely fruitful for many topics of stellar physics. Beyond these two initial objectives, CoRoT data revealed stellar variability associated with various other phenomena: granulation, rotational modulation by spots associated with magnetic activity, oblateness induced by a nearby companion star, ... The data of this CoRoT CDS archive correspond to the legacy release V4.4 of CoRoT N2 data. A complete description can be found in the "CoRoTN2versions_30sept2014.pdf" document available on the vizier ftp as well as on project websites listed in the "See also" field below. Other archives provide an access to the CoRoT data at different levels, or to complementary catalogues - the CoRoT IAS archive at idoc-corot.ias.u-psud.fr/ and mirrors of this archive at exoplanetarchive.ipac.caltech.edu/applications/ETSS/CoRoT_exo_index.html and at exoplanetarchive.ipac.caltech.edu/applications/ETSS/CoRoT_astero_index.html - archive at https://sipad-corot.cnes.fr/ or at the CoRoT IAS archive, but they require a deep understanding of the instrument and the observation conditions to be scientifically helpful. - Raw data N0 are available upon request at the CoRoT CNES archive. - Complementary data on the CoRoT targets, obtained through ground based complementary observations, can be found in :
- ID:
- ivo://CDS.VizieR/J/A+A/608/A103
- Title:
- 43 Cyg decorrelated 156-day light curve
- Short Name:
- J/A+A/608/A103
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photometric time series of the gamma Doradus star 43 Cyg obtained with the BRITE-Constellation nano-satellites allow us to study its pulsational properties in detail and to constrain its interior structure. We aim to find a g-mode period spacing pattern that allows us to determine the near-core rotation rate of 43 Cyg and redetermine the star's fundamental atmospheric parameters and chemical composition. We conducted a frequency analysis using the 156-days long data set obtained with the BRITE-Toronto satellite and employed a suite of MESA/GYRE models to derive the mode identification, asymptotic period spacing and near-core rotation rate. We also used high-resolution, high signal-to-noise ratio spectroscopic data obtained at the 1.2m Mercator telescope with the HERMES spectrograph to redetermine the fundamental atmospheric parameters and chemical composition of 43 Cyg using the software Spectroscopy Made Easy (SME). We detected 43 intrinsic pulsation frequencies and identified 18 of them to be part of a period spacing pattern consisting of prograde dipole modes with an asymptotic period spacing of 2970(+700,-570)s. The near-core rotation rate was determined to be 0.56(+0.12,-0.14)c/d. The atmosphere of 43 Cyg shows solar chemical composition at an effective temperature of 7150+/-150K, a logg of 4.2+/-0.6dex and a projected rotational velocity, vsini, of 44+/-4km/s. The morphology of the observed period spacing patterns shows indications of the presence of a significant chemical gradient in the stellar interior.
- ID:
- ivo://CDS.VizieR/B/dao
- Title:
- DAO Science Archive observations
- Short Name:
- B/dao
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The DAO archives are operated by the Canadian Astronomy Data Centre (CADC). These consist of two separate collections: the DAO Science Archive and the DAO Spectroscopic Plate Archive. The DAO Science Archive consists of modern electronic data obtained with the DAO's 1.8-m Plaskett telescope as well as the 1.2-m telescope and McKellar spectrograph. This collection is updated on a daily basis with new data and, as time permits, archival CCD data are also being added. The DAO spectroscopic plate collection in its entirety consists of over 16,800 high-dispersion spectrograms exposed at the coude focus of the 1.2-m DAO telescope and McKellar spectrograph between 1962 and 2000, and more than 93,000 secured at the Cassegrain focus of the DAO 1.8-m telescope and spectrograph between 1918 and 1984. The very great majority of those plates is now in the NRC-Herzberg plate archive. Since a programme to digitize them with the modified in-house PDS has only recently commenced (and with limited resources) there is currently a rather modest number of digital files available for download. However, if you have questions about the availability of plates of a target of particular interest you can we encourage you to contact Elizabeth Griffin or David Bohlender at NRC-Herzberg (elizabeth.griffin@nrc-cnrc.gc.ca), david.bohlender@nrc-cnrc.gc.ca) so that we can search the collection for plates that may be of interest to your research. Both archives allow searches by important criteria such as object name, date, and wavelength and presents the results of the search in a tabular format. The CADC's Data Retrieval facility allows archive users to download archival data directly to their own computers. Proprietary data can also be retrieved, but only by the Principal Investigator (PI) of the science program in question and any colleagues the PI has granted access to that program's data. These users must also register with the CADC in order to enable authorization tests to be made before such proprietary data is accessed. The proprietary period for DAO pixel data is 12 months from the time of the observation. Metadata associated with the pixel data (i.e. the FITS header) is public immediately. Because of uncertainties in the absolute pointing accuracy of the DAO telescopes, it is recommended that a relatively large search radius (e.g. 5') be used in any DAO archive searches for specific targets.
- ID:
- ivo://CDS.VizieR/V/51
- Title:
- Data Inventory of Space-Based Obs, Ver 1.1
- Short Name:
- V/51
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The "Data Inventory of Space-Based Celestial Observations Version 1.0" (DISCO) is a directory to data contained in sixteen catalogs dealing with observations from space. (Sounding rocket, solar, and planetary observations have been excluded.) The information extracted from the catalogs includes names of objects observed, 1950 equatorial coordinates, and the name of the catalog or instrument. A second file contains full references to the source catalogs and other pertinent information. The purpose of creating DISCO is (1) to unify astronomical observations from space, which are at present scattered and hard to locate, and then (2) to provide a machine-readable index to these observations, thus enabling easy access by computer. Such a directory will permit an astronomer to find out what objects have been observed from space, which spacecraft and instruments made the observations, and where to go to find the data themselves.
