Obscured or narrow-line active galaxies offer an unobstructed view of the quasar environment in the presence of a luminous and vigorously accreting black hole (BH). We exploit the large new sample of optically selected luminous narrow-line active galaxies from the Sloan Digital Sky Survey at redshifts 0.1<z<0.45, in conjunction with follow-up observations with the Low Dispersion Survey Spectrograph (LDSS3) at Magellan, to study the distributions of BH mass and host galaxy properties in these extreme objects.
We select a sample of 90 obscured (type 2) AGN with 1.45<z<3.05 from the zCOSMOS-deep galaxy sample by 5 sigma-detection of the high-ionization CIV {lambda}1549 narrow emission line. The presence of this feature in a galaxy spectrum is often associated with nuclear activity, and the selection effectiveness has been also confirmed by ultraviolet (UV) emission line ratio diagnostic diagrams. Applying the same selection technique, a sample of 102 unobscured (type 1) AGN was collected. Taking advantage of the large amount of multi-band data available in the COSMOS field, we investigate the properties of the CIV-selected type 2 AGN, focusing on their host galaxies, X-ray emission and UV emission lines. Finally, we investigate the physical properties of the ionized gas in the Narrow Line Region (NLR) of this type 2 AGN sample, combining the analysis of strong UV emission lines with predictions from photo-ionization models. We find that, in order to successfully reproduce the relative intensity of UV emission lines of the selected high-z type 2 AGN, two new ingredients in the photo-ionization models are fundamental,i.e. small inner radii of the NLR (~90pc for LAGN=10^45^erg/s) and the internal dissipative micro-turbulence of the gas emitting clouds (with v_micr_~100km/s). With these modified models, we compute the gas-phase metallicity of the NLR, and our measurements indicate a statistically significant evolution of the metal content with redshift. Finally, we do not observe, in our CIV-selected type 2 AGN sample, a strong relationship between the NLR gas metallicity and the stellar mass of the host galaxy.
Observation & radial velocity of WASP-150 & WASP-176
Short Name:
J/AJ/159/255
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report the discovery of two transiting exoplanets from the Wide Angle Search for Planets (WASP) survey, WASP-150b and WASP-176b. WASP-150b is an eccentric (e=0.38) hot Jupiter on a 5.6day orbit around a V=12.03, F8 main-sequence host. The host star has a mass and radius of 1.4M_{sun}_ and 1.7R_{sun}_ respectively. WASP-150b has a mass and radius of 8.5M_J_ and 1.1R_J_, leading to a large planetary bulk density of 6.4{rho}_J_. WASP-150b is found to be ~3Gyr old, well below its circularization timescale, supporting the eccentric nature of the planet. WASP-176b is a hot Jupiter planet on a 3.9day orbit around a V=12.01, F9 sub-giant host. The host star has a mass and radius of 1.3M{sun} and 1.9R{sun}. WASP-176b has a mass and radius of 0.86M_J_ and 1.5R_J_, respectively, leading to a planetary bulk density of 0.23{rho}_J_.
We report 370 measures of 170 components of binary and multiple-star systems, obtained from speckle imaging observations made with the Differential Speckle Survey Instrument (DSSI) at Lowell Observatory's Discovery Channel Telescope in 2015 through 2017. Of the systems studied, 147 are binary stars, 10 are seen as triple systems, and 1 quadruple system is measured. Seventy-six high-quality nondetections and 15 newly resolved components are presented in our observations. The uncertainty in relative astrometry appears to be similar to our previous work at Lowell, namely, linear measurement uncertainties of approximately 2mas, and the relative photometry appears to be uncertain at the 0.1-0.15mag level. Using these measures and those in the literature, we calculate six new visual orbits, including one for the Be star 66Oph and two combined spectroscopic-visual orbits. The latter two orbits, which are for HD22451 (YSC127) and HD185501 (YSC135), yield individual masses of the components at the level of 2% or better, and independent distance measures that in one case agrees with the value found in the Gaia DR2 and in the other disagrees at the 2{sigma} level. We find that HD22451 consists of an F6V+F7V pair with orbital period of 2401.1{+/-}3.2days and masses of 1.342{+/-}0.029 and 1.236{+/-}0.026M_{sun}_. For HD185501, both stars are G5 dwarfs that orbit one another with a period of 433.94{+/-}0.15days, and the masses are 0.898{+/-}0.012 and 0.876{+/-}0.012M_{sun}_. We discuss the details of both the new discoveries and the orbit objects.
We publish 16 Doppler imaging temperature maps for the years 1994-2002 of the active RS CVn star II Peg. The six maps from 1999-2002 are based on previously unpublished observations. Through Doppler imaging we want to study the spot evolution of the star and in particular compare this with previous results showing a cyclic spot behaviour and persistent active longitudes.
We report the discovery of HATS-71b, a transiting gas giant planet on a P=3.7955day orbit around a G=15.35mag M3 dwarf star. HATS-71 is the coolest M dwarf star known to host a hot Jupiter. The loss of light during transits is 4.7%, more than in any other confirmed transiting planet system. The planet was identified as a candidate by the ground-based HATSouth transit survey. It was confirmed using ground-based photometry, spectroscopy, and imaging, as well as space-based photometry from the NASA Transiting Exoplanet Survey Satellite mission (TIC234523599). Combining all of these data, and utilizing Gaia DR2, we find that the planet has a radius of 1.024{+/-}0.018R_J_ and mass of 0.37{+/-}0.24M_J_ (95% confidence upper limit of <0.80M_J_), while the star has a mass of 0.4861{+/-}0.0060M_{sun}_ and a radius of 0.4783{+/-}0.0060R_{sun}_.
The Observatoire de Haute-Provence (OHP) is situated in southeast France on a plateau at 650m altitude, near the village of St. Michel l'Observatoire, Alpes de Haute-Provence (southern French pre-Alps) at +44° latitude and 5.7° East longitude. Created in 1937 as a national facility for French astronomers, the facilities were made available for foreign visiting astronomers in 1949. It is owned by the Centre National de la Recherche Scientifique (CNRS) and is funded by the CNRS and the Institut National des Sciences de l'Univers (INSU). OHP is part the Marseille-Provence Astronomical Observatory (OAMP) federation. It provides a variety of optical telescopes, including the 1.93m telescope that features the cross-dispersed échelle spectrograph (Elodie).
The Observatory of Lyon is host to the Centre for Astronomical Reseach of Lyon (CRAL) is a Joined Research Unit (UMR 5574) of the University of Lyon 1 (UCBL), Ecole Normale Supérieure de Lyon (ENS-L), and Centre National de la Recherche Scientifique (CNRS). Projects include ELP-OA, HORIZON, NIRSpec for the James Webb Space Telescope, the Multi Unit Spectroscopic Explorer (MUSE), and the spectrum interpolater for the ELOIDE Library.
In this Letter, we present a search for Galactic red supergiant stars (RSGs) in the direction of the inner Galaxy. A total of 94 targets selected from the 2MASS (Cat. VII/233) and GLIMPSE I North (Benjamin et al. 2003, Cat. II/293; Churchwell et al. 2009PASP..121..213C) catalogs - via their blue extinction-free Q1 and Q2 colors - were spectroscopically observed at infrared wavelengths (in the H- and K-bands at R~1000), and an extraordinary high detection rate of RSGs (>61%) was found. We identified spectroscopically 58 RSGs, based on their flat continua and large equivalent widths of the CO-band at 2.293 {mu}m (EW>45 {AA}). This increase corresponds to about 25% of previously known RSGs in the Galactic region 10{deg}<l<60{deg}, -1.1{deg}<b<1.1{deg}. In order to confirm the location of the new RSGs in the inner Galaxy, distances were estimated for a subsample of 47 stars with the clump method and found to range from 3.6+/-0.4 to 8.6+/-0.7 kpc. The large new sample will allow us to investigate Galactic metallicity gradients as a function of galactocentric distances and azimuthal angles. Such information is currently an highly disputed issue to constrain models of Galaxy formation and evolution.
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