Very Low Mass Stellar and Substellar Companions to Solar-Like Stars From MARVELS V: A Low Eccentricity Brown Dwarf from the Driest Part of the Desert, MARVELS-6b

We describe the discovery of a likely brown dwarf (BD) companion with a minimum mass of 31.7 +/- 2.0 M_Jup to GSC 03546-01452 from the MARVELS radial velocity survey, which we designate as MARVELS-6b. For reasonable priors, our analysis gives a probability of 72% that MARVELS-6b has a mass below the hydrogen-burning limit of 0.072 M_Sun, and thus it is a high-confidence BD companion. It has a moderately long orbital period of 47.8929 +0.0063/-0.0062 days with a low eccentricty of 0.1442 +0.0078/-0.0073, and a semi-amplitude of 1644 +12/-13 m/s. Moderate resolution spectroscopy of the host star has determined the following parameters: T_eff = 5598 +/- 63, log g = 4.44 +/- 0.17, and [Fe/H] = +0.40 +/- 0.09. Based upon these measurements, GSC 03546-01452 has a probable mass and radius of M_star = 1.11 +/- 0.11 M_Sun and R_star = 1.06 +/- 0.23 R_Sun with an age consistent with less than ~6 Gyr at a distance of 219 +/- 21 pc from the Sun. Although MARVELS-6b is not observed to transit, we cannot definitively rule out a transiting configuration based on our observations. There is a visual companion detected with Lucky Imaging at 7.7 arcsec from the host star, but our analysis shows that it is not bound to this system. The minimum mass of MARVELS-6b exists at the minimum of the mass functions for both stars and planets, making this a rare object even compared to other BDs.Comment: 15 pages, 15 figures, 5 tables. Accepted for publication in The Astronomical Journa

Very-low-mass stellar and substellar companion to solar-like stars from MARVELS. III. A short-period brown dwarf cadidate around an active G0IV subgiant

We present an eccentric, short-period brown dwarf candidate orbiting the active, slightly evolved subgiant star TYC 2087-00255-1, which has effective temperature Teff = 5903±42 K, surface gravity log(g) = 4.07±0.16 (cgs), and metallicity [Fe/H] = −0.23 ± 0.07. This candidate was discovered using data from the first two years of the Multi-object APO Radial Velocity Exoplanets Large-area Survey, which is part of the third phase of Sloan Digital Sky Survey. From our 38 radial velocity measurements spread over a two-year time baseline, we derive a Keplerian orbital fit with semi-amplitude K = 3.571 ± 0.041 km s−1, period P = 9.0090 ± 0.0004 days, and eccentricity e = 0.226±0.011. Adopting a mass of 1.16±0.11M for the subgiant host star, we infer that the companion has a minimum mass of 40.0 ± 2.5MJup. Assuming an edge-on orbit, the semimajor axis is 0.090 ± 0.003 AU. The host star is photometrically variable at the ∼1% level with a period of ∼13.16±0.01 days, indicating that the host star spin and companion orbit are not synchronized. Through adaptive optics imaging we also found a point source 643 ± 10 mas away from TYC 2087-00255-1, which would have a mass of 0.13M if it is physically associated with TYC 2087-00255-1 and has the same age. Future proper motion observation should be able to resolve if this tertiary object is physically associated with TYC 2087-00255-1 and make TYC 2087-00255-1 a triple body system. Core Ca ii H and K line emission indicate that the host is chromospherically active, at a level that is consistent with the inferred spin period and measured vrot sin i, but unusual for a subgiant of this Teff . This activity could be explained by ongoing tidal spin-up of the host star by the companion

The Tenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-III Apache Point Observatory Galactic Evolution Experiment

The Sloan Digital Sky Survey (SDSS) has been in operation since 2000 April. This paper presents the Tenth Public Data Release (DR10) from its current incarnation, SDSS-III. This data release includes the first spectroscopic data from the Apache Point Observatory Galaxy Evolution Experiment (APOGEE), along with spectroscopic data from the Baryon Oscillation Spectroscopic Survey (BOSS) taken through 2012 July. The APOGEE instrument is a near-infrared R ~ 22,500 300 fiber spectrograph covering 1.514-1.696 mum. The APOGEE survey is studying the chemical abundances and radial velocities of roughly 100,000 red giant star candidates in the bulge, bar, disk, and halo of the Milky Way. DR10 includes 178,397 spectra of 57,454 stars, each typically observed three or more times, from APOGEE. Derived quantities from these spectra (radial velocities, effective temperatures, surface gravities, and metallicities) are also included. DR10 also roughly doubles the number of BOSS spectra over those included in the Ninth Data Release. DR10 includes a total of 1,507,954 BOSS spectra comprising 927,844 galaxy spectra, 182,009 quasar spectra, and 159,327 stellar spectra selected over 6373.2 deg2

Very low mass stellar and substellar companions to solar-like stars from MARVELS. II. A short-period companios orbiting an F star with evidence of a stellar tertiary and significant mutual inclination

We report the discovery via radial velocity (RV) measurements of a short-period (P = 2.430420±0.000006 days) companion to the F-type main-sequence star TYC 2930-00872-1. A long-term trend in the RV data also suggests the presence of a tertiary stellar companion with P > 2000 days. High-resolution spectroscopy of the host star yields Teff = 6427 ± 33 K, log g = 4.52 ± 0.14, and [Fe/H] = −0.04 ± 0.05. These parameters, combined with the broadband spectral energy distribution (SED) and a parallax, allow us to infer a mass and radius of the host star of M1 = 1.21 ± 0.08 M and R1 = 1.09+0.15 −0.13 R . The minimum mass of the inner companion is below the hydrogen-burning limit; however, the true mass is likely to be substantially higher. We are able to exclude transits of the inner companion with high confidence. Further, the host star spectrum exhibits a clear signature of Ca H and K core emission, indicating stellar activity, but a lack of photometric variability and small v sin I suggest that the primary’s spin axis is oriented in a pole-on configuration. The rotational period of the primary estimated through an activity–rotation relation matches the orbital period of the inner companion to within 1.5 σ, suggesting that the primary and inner companion are tidally locked. If the inner companion’s orbital angular momentum vector is aligned with the stellar spin axis as expected through tidal evolution, then it has a stellar mass of ∼0.3–0.4 M . Direct imaging limits the existence of stellar companions to projected separations <30 AU. No set of spectral lines and no significant flux contribution to the SED from either companion are detected, which places individual upper mass limits of M{2,3} 1.0 M , provided they are not stellar remnants. If the tertiary is not a stellar remnant, then it likely has a mass of ∼0.5–0.6M , and its orbit is likely significantly inclined from that of the secondary, suggesting that the Kozai–Lidov mechanism may have driven the dynamical evolution of this system

Acoustic Scale from the Angular Power Spectra of SDSS-III DR8 Photometric Luminous Galaxies

We measure the acoustic scale from the angular power spectra of the Sloan Digital Sky Survey III (SDSS-III) Data Release 8 imaging catalog that includes 872, 921 galaxies over ~10,000 deg2 between 0.45 ~ 0.35. We report constraints on cosmological parameters from our measurement in combination with the WMAP7 data and the previous spectroscopic BAO measurements of SDSS and WiggleZ. We refer to our companion papers (Ho et al. de Putter et al.) for investigations on information of the full power spectrum

Acoustic Scale from the Angular Power Spectra of SDSS-III DR8 Photometric Luminous Galaxies

We measure the acoustic scale from the angular power spectra of the Sloan Digital Sky Survey III (SDSS-III) Data Release 8 imaging catalog that includes 872, 921 galaxies over ~10,000 deg2 between 0.45 ~ 0.35. We report constraints on cosmological parameters from our measurement in combination with the WMAP7 data and the previous spectroscopic BAO measurements of SDSS and WiggleZ. We refer to our companion papers (Ho et al. de Putter et al.) for investigations on information of the full power spectrum

The Tenth Data Release of the sloan digital sky survey: first spectroscopic data from the SDSS-III Apache Point Observatory Galactic Evolution Experiment

The Sloan Digital Sky Survey (SDSS) has been in operation since 2000 April. This paper presents the Tenth Public Data Release (DR10) from its current incarnation, SDSS-III. This data release includes the first spectroscopic data from the Apache Point Observatory Galaxy Evolution Experiment (APOGEE), along with spectroscopic data from the Baryon Oscillation Spectroscopic Survey (BOSS) taken through 2012 July. The APOGEE instrument is a near-infrared R ~ 22,500 300 fiber spectrograph covering 1.514-1.696 mum. The APOGEE survey is studying the chemical abundances and radial velocities of roughly 100,000 red giant star candidates in the bulge, bar, disk, and halo of the Milky Way. DR10 includes 178,397 spectra of 57,454 stars, each typically observed three or more times, from APOGEE. Derived quantities from these spectra (radial velocities, effective temperatures, surface gravities, and metallicities) are also included. DR10 also roughly doubles the number of BOSS spectra over those included in the Ninth Data Release. DR10 includes a total of 1,507,954 BOSS spectra comprising 927,844 galaxy spectra, 182,009 quasar spectra, and 159,327 stellar spectra selected over 6373.2 deg2

The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: measurements of the growth of structure and expansion rate at z = 0.57 from anisotropic clustering

We analyse the anisotropic clustering of massive galaxies from the Sloan Digital Sky Survey III Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 9 (DR9) sample, which consists of 264 283 galaxies in the redshift range 0.43 0.57, and when combined imply OmegaLambda = 0.74 ± 0.016, independent of the Universe's evolution at z < 0.57. All of these constraints assume scale-independent linear growth, and assume general relativity to compute both O(10 per cent) non-linear model corrections and our errors. In our companion paper, Samushia et al., we explore further cosmological implications of these observations