- ID:
- ivo://CDS.VizieR/J/A+A/583/A115
- Title:
- FORS1 catalogue of stellar magnetic fields
- Short Name:
- J/A+A/583/A115
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The FORS1 instrument of the ESO Very Large Telescope was used to obtain low resolution circular polarized spectra of nearly a thousand of different stars, with the aim of measuring their mean longitudinal magnetic fields. Magnetic fields were measured by different authors, and using different methods and software tools. A catalogue of FORS1 magnetic measurements would provide a valuable resource with which to better understand the strengths and limitations of this instrument and of similar low-dispersion, Cassegrain spectropolarimeters. However, FORS1 data reduction has been carried out by a number of different groups using a variety of reduction and analysis techniques. Both our understanding of the instrument and our data reduction techniques have improved over time. A full re-analysis of FORS1 archive data using a consistent and fully documented algorithm would optimise the accuracy and usefulness of a catalogue of field measurements. Based on ESO FORS pipeline, we have developed a semi-automatic procedure for magnetic field determinations, which includes self-consistent checks for field detection reliability. We have applied our procedure to the full content of circular spectropolarimetric measurements of the FORS1 archive. We have produced a catalogue of spectro-polarimetric observations and magnetic field measurements for 1400 observations of 850 different objects. The spectral type of each object has been accurately classified. We have also been able to test different methods for data reduction is a systematic way. The resulting catalogue has been used to produce an estimator for an upper limit to the uncertainty in a field strength measurement of an early type star as a function of the signal-to-noise ratio of the observation. While FORS1 is not necessarily an optimal instrument for the discovery of weak magnetic fields, it is very useful for the systematic study of larger fields, such as those found in Ap/Bp stars and in white dwarfs.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/421/41
- Title:
- FORS Deep Field UV to blue photometry
- Short Name:
- J/A+A/421/41
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use the very deep and homogeneous I-band selected dataset of the FORS Deep Field (FDF) to trace the evolution of the luminosity function over the redshift range 0.5<z<5.0. We show that the FDF I-band selection down to I_AB_=26.8 misses of the order of 10% of the galaxies that would be detected in a K-band selected survey with magnitude limit K_AB_=26.3 (like FIRES). Photometric redshifts for 5558 galaxies are estimated based on the photometry in 9 filters (U, B, Gunn g, R, I, SDSS z, J, K and a special filter centered at 834nm).
- ID:
- ivo://CDS.VizieR/J/A+A/440/61
- Title:
- FORS spectroscopy of HDFS galaxies
- Short Name:
- J/A+A/440/61
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present low resolution multi-object spectroscopy of an I-band magnitude limited (I_AB_~23-23.5) sample of galaxies located in an area centered on the Hubble Deep Field-South (HDFS). The observations were obtained using the Focal Reducer/low dispersion Spectrograph (FORS) on the ESO Very Large Telescope. Thirty-two primary spectroscopic targets in the HST-WFPC2 HDFS were supplemented with galaxies detected in the Infrared Space Observatory's survey of the HDFS and the ESO Imaging Deep Survey to comprise a sample of 100 galaxies for spectroscopic observations. Based on detections of several emission lines, such as [OII]3727, H{beta} and [OIII]5007, or of other spectroscopic features, we measured accurate redshifts for 50 objects in the central HDFS and flanking fields. The redshift range of the current sample of galaxies is 0.6-1.2, with a median redshift of 1.13 (at I~23.5 not corrected for completeness). The sample is dominated by starburst galaxies with only a small fraction of ellipticals (~10%). For the emission line objects, the extinction corrected [OII]3727 line strengths yield estimates of star formation rates in the range 0.5-30M_{sun}_/yr. We used the present data to derive the [OII]3727 luminosity function up to redshift of 1.2. When combined with [OII]3727 luminosity densities for the local and high redshift Universe, our results confirm the steep rise in the star formation rate (SFR) to z~1.3.
- ID:
- ivo://CDS.VizieR/J/A+A/596/A47
- Title:
- FORS2 transmission spectroscopy of WASP-17b
- Short Name:
- J/A+A/596/A47
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present FORS2 (attached to ESO's Very Large Telescope) observations of the exoplanet WASP-17b during its primary transit, for the purpose of differential spectrophotometry analysis. We use the instrument in its Mask eXchange Unit (MXU) mode to simultaneously obtain low resolution spectra of the planet hosting star, as well as several reference stars in the field of view. The integration of these spectra within broadband and smaller 100{AA} bins provides us with 'white' and spectrophotometric light curves, from 5700 to 8000{AA}. Through modelling the white light curve, we obtain refined bulk and transit parameters of the planet, as well as wavelength-dependent variations of the planetary radius from smaller spectral bins through which the transmission spectrum is obtained. The inference of transit parameters, as well as the noise statistics, is performed using a Gaussian Process model. We achieve a typical precision in the transit depth of a few hundred parts per million from various transit light curves. From the transmission spectra we rule out a flat spectrum at >3{sigma} and detect marginal presence of the pressure-broadened sodium wings. Furthermore, we detect the wing of the potassium absorption line in the upper atmosphere of the planet with 3-{sigma} confidence, both facts pointing to a relatively shallow temperature gradient in the atmosphere. These conclusions are mostly consistent with previous studies of this exo-atmosphere, although previous potassium measurements have been inconclusive.
6455. Fossil galaxy groups
- ID:
- ivo://CDS.VizieR/J/AJ/137/3942
- Title:
- Fossil galaxy groups
- Short Name:
- J/AJ/137/3942
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use SDSS-DR4 photometric and spectroscopic data out to redshift z~0.1 combined with ROSAT All Sky Survey X-ray data to produce a sample of 25 fossil groups (FGs), defined as bound systems dominated by a single, luminous elliptical galaxy with extended X-ray emission. We examine possible biases introduced by varying the parameters used to define the sample, and the main pitfalls are also discussed.
- ID:
- ivo://CDS.VizieR/J/MNRAS/475/193
- Title:
- Foundation Supernova Survey first data release
- Short Name:
- J/MNRAS/475/193
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Foundation Supernova Survey aims to provide a large, high-fidelity, homogeneous, and precisely calibrated low-redshift Type Ia supernova (SN Ia) sample for cosmology. The calibration of the current low-redshift SN sample is the largest component of systematic uncertainties for SN cosmology, and new data are necessary to make progress. We present the motivation, survey design, observation strategy, implementation, and first results for the Foundation Supernova Survey. We are using the Pan-STARRS telescope to obtain photometry for up to 800 SNe Ia at z<~0.1. This strategy has several unique advantages: (1) the Pan-STARRS system is a superbly calibrated telescopic system, (2) Pan-STARRS has observed 3/4 of the sky in grizyP1 making future template observations unnecessary, (3) we have a well-tested data-reduction pipeline, and (4) we have observed ~3000 high-redshift SNe Ia on this system. Here, we present our initial sample of 225 SN Ia grizP1 light curves, of which 180 pass all criteria for inclusion in a cosmological sample. The Foundation Supernova Survey already contains more cosmologically useful SNe Ia than all other published low-redshift SN Ia samples combined. We expect that the systematic uncertainties for the Foundation Supernova Sample will be two to three times smaller than other low-redshift samples. We find that our cosmologically useful sample has an intrinsic scatter of 0.111mag, smaller than other low-redshift samples. We perform detailed simulations showing that simply replacing the current low-redshift SN Ia sample with an equally sized Foundation sample will improve the precision on the dark energy equation-of-state parameter by 35 per cent, and the dark energy figure of merit by 72 per cent.
- ID:
- ivo://CDS.VizieR/J/MNRAS/451/2735
- Title:
- Four close dSph XXM observations
- Short Name:
- J/MNRAS/451/2735
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of the analysis of deep archival XMM-Newton observations towards the dwarf spheroidal galaxies Draco, Leo I, Ursa Major II (UMa II) and Ursa Minor (UMi) in the Milky Way neighbourhood. The X-ray source population is characterized and cross-correlated with available databases to infer their nature. We also investigate if intermediate-mass black holes are hosted in the centre of these galaxies. For Draco, we detect 96 high-energy sources, two of them possibly being local stars, while no evidence for any X-ray emitting central compact object is found. Towards the Leo I and UMa II fields of view, we reveal 116 and 49 X-ray sources, respectively. None of them correlates with the putative central black holes and only one is likely associated with a UMa II local source. The study of the UMi dwarf galaxy found 54 high-energy sources and a possible association with a source at the dwarf spheroidal galaxy centre. We put an upper limit on the luminosity of the central compact object of 4.02x10^33^erg/s. Furthermore, via the correlation with a radio source near the galactic centre, the putative black hole should have a mass of (2.76^+32.00^_-2.54_)x10^6^M_{sun}_ and be radiatively inefficient. This confirms a previous result obtained using Chandra data alone.
- ID:
- ivo://CDS.VizieR/J/A+A/650/A173
- Title:
- Four Herbig-Haro objects SOFIA/FIFI-LS images
- Short Name:
- J/A+A/650/A173
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- We present SOFIA/FIFI-LS observations of three Class 0 and one Class I outflows (Cep E, HH 1, HH 212, and L1551 IRS5) in the far-infrared [OI]63um and [OI]145um transitions. Spectroscopic [OI]63um maps enable us to infer the spatial extent of warm (T~500-1200K), low-excitation atomic gas within these protostellar outflows. Our main goal is to determine mass-loss rates from the obtained [OI]63um maps and compare these with accretion rates from other studies. The far-infrared [OI]63um emission line is predicted to be the main coolant of dense, dissociative J-shocks caused by decelerated wind or jet shocks. If proper shock conditions prevail, the instantaneous mass-ejection rate is directly connected to the [OI]63um luminosity. In order to unravel evolutionary trends we analyse a set of 14 Class 0/I outflow sources that have been spatially resolved in the [OI]63um emission. We compare these data with a sample of 74 Class 0/I/II outflow sources that have been observed with Herschel (WISH, DIGIT, WILL, GASPS surveys) without spatially resolving the [OI]63um line.
- ID:
- ivo://CDS.VizieR/J/A+A/506/95
- Title:
- Fourier analysis of HD 49330 CoRoT light curve
- Short Name:
- J/A+A/506/95
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Be stars undergo outbursts producing a circumstellar disk from the ejected material. The beating of non-radial pulsations has been put forward as a possible mechanism of ejection. We analyze the pulsational behavior of the early B0.5IVe star HD 49330 observed during the first CoRoT long run towards the Galactical anticenter (LRA1). This Be star is located close to the lower edge of the {beta} Cephei instability strip in the HR diagram and showed a 0.03mag outburst during the CoRoT observations. It is thus an ideal case for testing the aforementioned hypothesis.
- ID:
- ivo://CDS.VizieR/J/MNRAS/438/2440
- Title:
- Fourier analysis of 13095 LMC RR Lyr stars
- Short Name:
- J/MNRAS/438/2440
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a careful and detailed light-curve analysis of publicly available I-band data on fundamental mode RR Lyrae (RRab) stars of the Large Magellanic Cloud (LMC) obtained by the Optical Gravitational Lensing Experiment phase-III project. Using the Fourier parameters of 13095 RRab stars, metallicities and absolute magnitudes of individual stars are obtained. The representation of stars on the P-{phi}_31_^V^ plane shows the existence of three significant metallicity groups with mean metallicities as -1.20+/-0.12, -1.57+/-0.10 and -1.89+/-0.09dex. The corresponding absolute magnitudes of these three groups are obtained as 0.70+/-0.08, 0.59+/-0.06 and 0.49+/-0.08mag, respectively. Distribution of these three groups as a function of vertical |z| distance indicates that the formation of the LMC disc predates the formation of the inner halo. Issue of the existence of a metallicity gradient as a function of galactocentric distances has also been addressed. Approximating the structure of the LMC disc as a triaxial ellipsoid, the inclination angle (i) relative to the plane of the sky and the position angle of the line of nodes ({theta}_lon_) were estimated as 24.20{deg} and 176.01{deg}, respectively. The axes ratios and the eccentricity were also determined using the principal axis transformation method.