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Related papers: M-Dwarfs at Large Heliocentric Distances

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Deep imaging and spectroscopy have been carried out for optical counterparts of a sample of 68 faint radio sources (S > 0.2 mJy) in the ``Marano Field''. About 60% of the sources have been optically identified on deep CCD exposures (limit R…

Astrophysics · Physics 2009-10-31 Carlotta Gruppioni , Marco Mignoli , Gianni Zamorani

We have followed up on the results of a 65 square degree CFHT/MegaCam imaging survey of the nearby M81 Group searching for faint and ultra-faint dwarf galaxies. The original survey turned up 22 faint candidate dwarf members. Based on…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Kristin Chiboucas , Bradley A. Jacobs , R. Brent Tully , Igor D. Karachentsev

A metal-rich environment facilitates planet formation, making metal-rich stars the most favorable targets for surveys seeking to detect new exoplanets. Using this advantage to identify likely low-mass planet hosts, however, has been…

Solar and Stellar Astrophysics · Physics 2012-03-15 Barbara Rojas-Ayala , Kevin R. Covey , Philip S. Muirhead , James P. Lloyd

Recent interferometric surveys of nearby main-sequence stars show a faint but significant near-infrared excess in roughly two dozen systems, i.$\,$e. around $10\,\%$ to $30\,\%$ of stars surveyed. This excess is attributed to dust located…

Solar and Stellar Astrophysics · Physics 2017-02-01 Florian Kirchschlager , Sebastian Wolf , Alexander V. Krivov , Harald Mutschke , Robert Brunngräber

Wide-orbit ($>$10 AU) gas giant planets shape the architecture of planetary systems, yet their occurrence rate remains poorly constrained. JWST has obtained the deepest mid-infrared images of nearby stars to date through substantial MIRI…

Aims. We use different tracers, such as Ha, ultraviolet (UV), and infrared (IR) emissions at various wavelengths, to study the dust and star-formation (SF) conditions throughout the disk of M33. Methods. We derive the radial distribution of…

Astrophysics · Physics 2009-11-13 S. Verley , E. Corbelli , C. Giovanardi , L. K. Hunt

We present mid-infrared spectra of sixteen optically faint sources with 70 micron fluxes in the range 19-38mJy. The sample spans a redshift range of 0.35<z<1.9, with most lying between 0.8<z<1.6, and has infrared luminosities of 10^{12} -…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-18 D. Farrah , D. Weedman , C. Lonsdale , M. Polletta , M. Rowan-Robinson , J. Houck , H. Smith

The sensitivity available to near-infrared surveys has recently allowed us to probe the galaxy population at $z\approx 7$ and beyond. The existing {\em Hubble} Wide Field Camera 3 (WFC3) and the Visible and Infrared Survey Telescope for…

Astrophysics of Galaxies · Physics 2014-03-05 Stephen M. Wilkins , Elizabeth R. Stanway , Malcolm N. Bremer

We analyze the outer regions of M33, beyond 15 kpc in projected distance from its center using Subaru/HSC multi-color imaging. We identify Red Giant Branch (RGB) stars and Red Clump (RC) stars using the surface gravity sensitive $NB515$…

We have obtained infrared (1 to 2.5 micron) spectroscopy for 42 halo and disk dwarfs with spectral type M1 to M6.5. These data are compared to synthetic spectra generated by the latest model atmospheres of Allard & Hauschildt. Photospheric…

Astrophysics · Physics 2009-05-29 S. K. Leggett , F. Allard , Conard Dahn , P. H. Hauschildt , T. H. Kerr , J. Rayner

We present an empirical near-infrared (NIR) spectroscopic method for estimating M dwarf metallicities, based on features in the H-band, as well as an implementation of a similar published method in the K-band. We obtained R~2000 NIR spectra…

Solar and Stellar Astrophysics · Physics 2015-06-04 Ryan C. Terrien , Suvrath Mahadevan , Chad F. Bender , Rohit Deshpande , Lawrence W. Ramsey , John J. Bochanski

We identified 46 unresolved source candidates in the Hubble Ultra Deep Field, down to i775 = 29.5. Unresolved objects were identified using a parameter S, which measures the deviation from the curve-of-growth of a point source. Extensive…

Deep UBRI images of a 15'x15' field in the M31 galaxy's outer spheroid obtained with the KPNO 4-m telescope, and Keck 10-m telescope+LRIS I-band images, are used to isolate candidate red giant branch stars located at R=19 kpc (projected)…

Astrophysics · Physics 2009-10-30 David B. Reitzel , Puragra Guhathakurta , Andrew Gould

We use deep ground-based imaging in the near-IR to search for counterparts to the luminous submm sources in the catalog of Smail et al (1998). For the majority of the submm sources the near-IR imaging supports the counterparts originally…

With the William Herschel Telescope in La Palma we made IJKs observations of an area of about 40'x30' of the Local Group galaxy Draco. This allows us to describe Draco's late-type stellar population across the whole galaxy at a photometric…

Astrophysics · Physics 2009-11-11 M. -R. L. Cioni , H. J. Habing

Using data derived from the deepest and finest angular resolution images of the universe yet acquired by astronomers at optical wavelengths using the Hubble Space Telescope (HST) in two postage-stamp sections of the sky (Williams et al.…

Astrophysics · Physics 2009-10-31 R. A. Méndez , D. Minniti

We present new horizontal branch (HB) distance measurements to 17 of the faintest known M31 satellites ($-6 \lesssim M_{V} \lesssim -13$) based on deep Hubble Space Telescope (HST) imaging. The color-magnitude diagrams extend $\sim$1-2…

Parallaxes are presented for a sample of 20 nearby dwarf carbon stars. The inferred luminosities cover almost two orders of magnitude. Their absolute magnitudes and tangential velocities confirm prior expectations that some originate in the…

The reduced proper motion diagram (RPMD) for a complete sample of faint stars with high accuracy proper motions in the North Galactic Pole field SA57 is investigated. Eight stars with very large reduced proper motions are identified as…

Astrophysics · Physics 2009-11-07 S. R. Majewski , M. H. Siegel

[Abridged] We present a search for fast optical transients (~0.5 hr-1 day) using repeated observations of the Pan-STARRS1 Medium-Deep Survey (PS1/MDS) fields. Our search takes advantage of the consecutive g/r-band observations (16.5 min in…