- ID:
- ivo://CDS.VizieR/J/A+A/539/A159
- Title:
- WASP-4b transit griz light curves
- Short Name:
- J/A+A/539/A159
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Ground-based simultaneous multiband transit observations allow an accurate system parameter determination and may lead to the detection and characterization of additional bodies via the transit timing variations (TTVs) method. We aim to (i) characterize the heavily bloated WASP-4b hot Jupiter and its star by measuring system parameters and the dependence of the planetary radius as a function of four (Sloan g', r', i', z') wavelengths and (ii) search for TTVs.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/430/2932
- Title:
- WASP-44 griz light curves
- Short Name:
- J/MNRAS/430/2932
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present ground-based broad-band photometry of two transits in the WASP-44 planetary system obtained simultaneously through four optical (Sloan g', r', i', z') and three near-infrared (NIR; J, H, K) filters. We achieved low scatters of 1-2mmag per observation in the optical bands with a cadence of roughly 48s, but the NIR-band light curves present much greater scatter. We also observed another transit of WASP-44 b by using a Gunn r filter and telescope defocussing, with a scatter of 0.37 mmag per point and an observing cadence around 135 s. We used these data to improve measurements of the time of mid- transit and the physical properties of the system. In particular, we improved the radius measurements of the star and planet by factors of 3 and 4, respectively. We find that the radius of WASP-44 b is 1.002+/-0.033+/-0.018RJup (statistical and systematic errors, respectively), which is slightly smaller than previously thought and differs from that expected for a core-free planet. In addition, with the help of a synthetic spectrum, we investigated the theoretically predicted variation of the planetary radius as a function of wavelength, covering the range 370-2440nm. We can rule out extreme variations at optical wavelengths, but unfortunately our data are not precise enough (especially in the NIR bands) to differentiate between the theoretical spectrum and a radius which does not change with wavelength. The resulting measurements of transit mid-points were fitted with a straight line to obtain a new orbital ephemeris: T0=BJD(TDB)2455434.37642(37)+2.4238133(23)xE, where E is the number of orbital cycles after the reference epoch [the mid-point of the first transit observed by Anderson et al. (2012, Cat. J/MNRAS/422/1988)] and quantities in parentheses denote the uncertainty in the final digit of the preceding number.
- ID:
- ivo://CDS.VizieR/J/A+A/642/A50
- Title:
- WASP-74 griz_s_ light curves
- Short Name:
- J/A+A/642/A50
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new transit observations of the hot Jupiter WASP-74 b (Teq~1860K) using the high-resolution spectrograph HARPS-N and the multi-colour simultaneous imager MuSCAT2. We refined the orbital properties of the planet and its host star and measured its obliquity for the first time. The measured sky-projected angle between the stellar spin-axis and the orbital axis of the planet is compatible with an orbit that is well-aligned with the equator of the host star ({lambda}=0.77+/-0.99{deg}). We are not able to detect any absorption feature of H{alpha} or any other atomic spectral features in the high-resolution transmission spectra of this source owing to low S/N at the line cores. Despite previous claims regarding the presence of strong optical absorbers such as TiO and VO gases in the atmosphere of WASP-74 b, new ground-based photometry combined with a reanalysis of previously reported observations from the literature show a slope in the low-resolution transmission spectrum that is steeper than expected from Rayleigh scattering alone.
- ID:
- ivo://CDS.VizieR/J/AJ/154/118
- Title:
- WD+dMs from the SUPERBLINK proper motion survey
- Short Name:
- J/AJ/154/118
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an activity and kinematic analysis of high proper motion white dwarf-M dwarf binaries (WD+dMs) found in the SUPERBLINK survey, 178 of which are new identifications. To identify WD+dMs, we developed a UV-optical-IR color criterion and conducted a spectroscopic survey to confirm each candidate binary. For the newly identified systems, we fit the two components using model white dwarf spectra and M dwarf template spectra to determine physical parameters. We use H{alpha} chromospheric emission to examine the magnetic activity of the M dwarf in each system, and investigate how its activity is affected by the presence of a white dwarf companion. We find that the fraction of WD+dM binaries with active M dwarfs is significantly higher than their single M dwarf counterparts at early and mid-spectral types. We corroborate previous studies that find high activity fractions at both close and intermediate separations. At more distant separations, the binary fraction appears to approach the activity fraction for single M dwarfs. Using derived radial velocities and the proper motions, we calculate 3D space velocities for the WD+dMs in SUPERBLINK. For the entire SUPERBLINK WD+dMs, we find a large vertical velocity dispersion, indicating a dynamically hotter population compared to high proper motion samples of single M dwarfs. We compare the kinematics for systems with active M dwarfs and those with inactive M dwarfs, and find signatures of asymmetric drift in the inactive sample, indicating that they are drawn from an older population.
- ID:
- ivo://CDS.VizieR/J/ApJS/243/15
- Title:
- WERGS. II. SED fitting with optical, IR & radio data
- Short Name:
- J/ApJS/243/15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present physical properties of radio galaxies (RGs) with f_1.4GHz_>1mJy discovered by Subaru Hyper Suprime-Cam (HSC) and Very Large Array Faint Images of the Radio Sky at Twenty-Centimeters (FIRST) survey. For 1056 FIRST RGs at 0<z<=1.7 with HSC counterparts in about 100deg^2^, we compiled multi-wavelength data of optical, near-infrared (IR), mid-IR, far-IR, and radio (150MHz). We derived their color excess (E(B-V)_*_), stellar mass, star formation rate (SFR), IR luminosity, the ratio of IR and radio luminosity (q_IR_), and radio spectral index ({alpha}_radio_) that are derived from the spectral energy distribution (SED) fitting with CIGALE. We also estimated Eddington ratio based on stellar mass and integration of the best-fit SEDs of active galactic nucleus (AGN) component. We found that E(B-V)_*_, SFR, and IR luminosity clearly depend on redshift while stellar mass, q_IR_, and {alpha}_radio_ do not significantly depend on redshift. Since optically faint (i_AB_>=21.3) RGs that are newly discovered by our RG survey tend to be high redshift, they tend to not only have a large dust extinction and low stellar mass but also have high SFR and AGN luminosity, high IR luminosity, and high Eddington ratio compared with optically bright ones. The physical properties of a fraction of RGs in our sample seem to differ from a classical view of RGs with massive stellar mass, low SFR, and low Eddington ratio, demonstrating that our RG survey with HSC and FIRST provides us curious RGs among entire RG population.
- ID:
- ivo://CDS.VizieR/J/MNRAS/446/3797
- Title:
- Westerlund 2 UBVIc photometry
- Short Name:
- J/MNRAS/446/3797
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep UBVI_c_ photometric data of the young open cluster Westerlund 2. An abnormal reddening law of R_V,cl_=4.14+/-0.08 was found for the highly reddened early-type members (E(B-V)>=1.45), whereas a fairly normal reddening law of R_V,fg_=3.33+/-0.03 was confirmed for the foreground early-type stars (E(B-V)_fg_<1.05). The distance modulus was determined from zero-age main-sequence fitting to the reddening-corrected colour-magnitude diagram of the early-type members to be V_0_-M_V_=13.9+/-0.14 (random error) _-0.1_^+0.4^ (the upper limit of systematic error) mag (d=6.0+/-0.4_-0.3_^+1.2^kpc). To obtain te initial mass function, pre-main-sequence (PMS) stars were selected by identifying the optical counterparts of Chandra X-ray sources and mid-infrared emission stars from the Spitzer GLIMPSE (Galactic Legacy Infrared Mid-Plane Survey Extraordinaire) source catalogue. The initial mass function shows a shallow slope of {Gamma}=-1.1+/-0.1 down to log(m)=0.7. The total mass of Westerlund 2 is estimated to be at least 7400M_{sun}_. The age of Westerlund 2 from the main-sequence turn-on and PMS stars is estimated to be <~1.5Myr. We confirmed the existence of a clump of PMS stars located ~1-arcmin north of the core of Westerlund 2, but we could not find any clear evidence for an age difference between the core and the northern clump.
- ID:
- ivo://CDS.VizieR/II/249
- Title:
- WHAM Northern Sky Survey, V-1.1
- Short Name:
- II/249
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Wisconsin H-Alpha Mapper has been designed to produce a survey of H-Alpha emission from the interstellar medium (ISM) over the entire northern sky. The instrument combines a 0.6 meter telescope and a dual-etalon 15cm Fabry-Perot spectrometer. In the primary spectral mode, an exposure captures a 200km/s spectral region with 8-12km/s velocity resolution from a one-degree beam on the sky. With a large-aperture design and modern CCD technology, WHAM can detect Galactic emission as faint as 0.05 Rayleighs in a 30 second exposure. For gas at 10000K, this observed intensity corresponds to an emission measure of about 0.1cm^-6^pc, more than 10 million times fainter than the Orion Nebula.
- ID:
- ivo://CDS.VizieR/J/MNRAS/462/2506
- Title:
- White dwarf candidates in DECam first field
- Short Name:
- J/MNRAS/462/2506
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first results from a minute cadence survey of a 3deg^2^ field obtained with the Dark Energy Camera. We imaged part of the Canada-France-Hawaii Telescope Legacy Survey area over eight half-nights. We use the stacked images to identify 111 high proper motion white dwarf candidates with g<=24.5mag and search for eclipse-like events and other sources of variability. We find a new g=20.64mag pulsating ZZ Ceti star with pulsation periods of 11-13min. However, we do not find any transiting planetary companions in the habitable zone of our target white dwarfs. Given the probability of eclipses of 1 per cent and our observing window from the ground, the non-detection of such companions in this first field is not surprising. Minute cadence DECam observations of additional fields will provide stringent constraints on the frequency of planets in the white dwarf habitable zone.
- ID:
- ivo://CDS.VizieR/J/MNRAS/448/2260
- Title:
- White dwarf candidates in SDSS DR10
- Short Name:
- J/MNRAS/448/2260
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a method which uses cuts in colour-colour and reduced proper motion-colour space to select white dwarfs without the recourse to spectroscopy while allowing an adjustable compromise between completeness and efficiency. Rather than just producing a list of white dwarf candidates, our method calculates a probability of being a white dwarf (P_WD_) for any object with available multiband photometry and proper motion. We applied this method to all objects in the Sloan Digital Sky Survey (SDSS) Data Release 10 (DR10) photometric footprint and to a few selected sources in DR7 which did not have reliable photometry in DR9 or DR10. This application results in a sample of 61 969 DR10 and 3799 DR7 photometric sources with calculated P_WD_ from which it is possible to select a sample of ~23000 high-fidelity white dwarf candidates with T_eff_>~7000K and g<=19. This sample contains over 14000 high confidence white dwarfs candidates which have not yet received spectroscopic follow-up. These numbers show that, to date, the spectroscopic coverage of white dwarfs in the SDSS photometric footprint is, on average, only ~40 percent complete. While we describe here in detail the application of our selection to the SDSS catalogue, the same method could easily be applied to other multicolour, large area surveys. We also publish a list of 8701 bright (g<=19) white dwarfs with SDSS spectroscopy, of which 1781 are new identifications in DR9/DR10.
- ID:
- ivo://CDS.VizieR/J/MNRAS/452/765
- Title:
- White dwarf candidates using LAMOST DR3
- Short Name:
- J/MNRAS/452/765
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In previous work by Gentile Fusillo et al., we developed a selection method for white dwarf candidates which makes use of photometry, colours and proper motions to calculate a probability of being a white dwarf (P_WD_). The application of our method to the Sloan Digital Sky Survey (SDSS) data release 10 resulted in =~ 66000 photometrically selected objects with a derived P_WD_, approximately =~21000 of which are high-confidence white dwarf candidates. Here, we present an independent test of our selection method based on a sample of spectroscopically confirmed white dwarfs from the Large Sky Area Multi-Fiber Spectroscopic Telescope (LAMOST) survey. We do this by cross-matching all our =~66000 SDSS photometric white dwarf candidates with the over 4 million spectra available in the third data release of LAMOST. This results in 1673 white dwarf candidates with no previous SDSS spectroscopy, but with available LAMOST spectra. Among these objects, we identify 309 genuine white dwarfs. We find that our P_WD_ can efficiently discriminate between confirmed LAMOST white dwarfs and contaminants. Our white dwarf candidate selection method can be applied to any multiband photometric survey and in this work we conclusively confirm its reliability in selecting white dwarfs without recourse to spectroscopy. We also discuss the spectroscopic completeness of white dwarfs in LAMOST, as well as deriving effective temperatures, surface gravities and masses for the hydrogen-rich atmosphere white dwarfs in the newly identified LAMOST sample.
