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Optical and near-mid-infrared reverberation mapping data obtained at Universit\"{a}tssternwarte Bochum in Chile and with the Spitzer Space Telescope allow us to explore the geometry of both the H$\alpha$ BLR and the dust torus for the…

Astrophysics of Galaxies · Physics 2018-10-03 C. Sobrino Figaredo , F. Pozo Nuñez , M. Ramolla , M. Haas , R. Chini , K. Hodapp , S. Willner , M. Ashby

We present the first simultaneous, multi-wavelength observations of an L dwarf, the L3.5 candidate brown dwarf 2MASS J00361617+1821104, conducted with the Very Large Array, the Chandra X-ray Observatory, and the Kitt Peak 4-m telescope. We…

Near-infrared medium-resolution spectra of seven bright brown dwarfs are presented. The spectra were obtained with the Infrared Camera (IRC) on board the infrared astronomical satellite AKARI, covering 2.5--5.0 um with a spectral resolution…

Solar and Stellar Astrophysics · Physics 2015-05-19 Issei Yamamura , Takashi Tsuji , Toshihiko Tanabe

We present new high spatial resolution (<~ 0.1") 1-5 micron adaptive optics images, interferometric 1.3 mm continuum and 12CO 2-1 maps, and 350 micron, 2.8 and 3.3 mm fluxes measurements of the HV Tau system. Our adaptive optics images…

We present a UVES/VLT high resolution atlas of three L dwarfs and one T dwarf system, spectral classes at which most of the objects are brown dwarfs. Our atlas covers the optical region from H$\alpha$ up to the near infrared at 1 $\mu$m. We…

Astrophysics · Physics 2009-11-13 A. Reiners , D. Homeier , P. H. Hauschildt , F. Allard

We present the first results from applying the spectral inversion technique in the cloudy L dwarf regime. Our new framework provides a flexible approach to modelling cloud opacity which can be built incrementally as the data requires, and…

Blazar S5 0716+714 is well-known for its short-term variability, down to intra-day time-scales. We here present the 2-min cadence optical light curve obtained by the TESS space telescope in 2019 December - 2020 January and analyse the…

We present the detection of day-timescale periodic variability in the r-band lightcurve of newly outbursting FU Orionis-type object HBC 722, taken from > 42 nights of observation with the CQUEAN instrument on the McDonald Observatory 2.1m…

We present time-resolved spectroscopy and photometry of the cataclysmic variable (CV) SDSSJ133941.11+484727.5 (SDSS1339) which has been discovered in the Sloan Digital Sky Survey Data Release 4. The orbital period determined from radial…

Mrk 421 is the first TeV blazar found to exhibit significant spectral variability during strong flaring activity, showing hardening of the TeV spectrum in high emission states. Mrk 421 is also known to exhibit flux variability on time…

Astrophysics · Physics 2009-09-29 F. Krennrich , I. H. Bond , P. J. Boyle , S. M. Bradbury , J. H. Buckley

We present results of high-resolution imaging toward HL Tau by the Combined Array for Research in Millimeter-wave Astronomy (CARMA). We have obtained 1.3 and 2.7 mm dust continua with an angular resolution down to 0.13 arc second. Through…

Solar and Stellar Astrophysics · Physics 2015-05-28 Woojin Kwon , Leslie W. Looney , Lee G. Mundy

We present radial-velocity measurements obtained using high- and intermediate-resolution spectroscopic observations of the classical T Tauri star UZ Tau East obtained from 1994 to 1996. We also provide measurements of H$\alpha$ equivalent…

Astrophysics · Physics 2009-11-10 Eduardo L. Martín , Antonio Magazzù , Xavier Delfosse , Robert D. Mathieu

We present a detailed pulse phase resolved spectral analysis of the persistent high mass X-ray binary pulsar Vela X-1 observed with Suzaku during June 2008. The pulse profiles exhibit both intensity and energy dependence with multiple peaks…

High Energy Astrophysical Phenomena · Physics 2015-06-12 Chandreyee Maitra , Biswajit Paul

We report on the spectroscopic confirmation of 68 new bright ($G=13.5-17.2$ mag) and blue (pre-)white dwarfs (WDs). This finding has allowed us to almost double the number of the hottest ($T_{\mathrm{eff}} \geq 60$kK) known WDs brighter…

We report multi-epoch radial velocities, rotational velocities, and atmospheric parameters for 37 T-type brown dwarfs observed with Keck/NIRSPEC. Using a Markov Chain Monte Carlo forward-modeling method, we achieve median precisions of 0.5…

Among the greatest challenges in understanding ultra-cool brown dwarf and exoplanet atmospheres is the evolution of cloud structure as a function of temperature and gravity. In this study, we present the rotational modulations of GU Psc b…

In this work we examine M dwarf rotation rates at a range of ages to establish benchmarks for Mdwarf gyrochronology. This work includes a sample of 713 spectroscopically-classified M0-M8 dwarfs with new rotation rates measured from K2 light…

Solar and Stellar Astrophysics · Physics 2021-08-11 Mark Popinchalk , Jacqueline K. Faherty , Rocio Kiman , Jonathan Gagné , Jason L. Curtis , Ruth Angus , Kelle L. Cruz , Emily L. Rice

We present the detection of rotationally modulated, circularly polarized radio emission from the T8 brown dwarf WISE J062309.94-045624.6 between 0.9 and 2.0 GHz. We detected this high proper motion ultracool dwarf with the Australian SKA…

The signatures of dust processing and grain growth - related to the formation of rocky planets - are easily seen in mid-infrared spectral features. One important diagnostic tool in this context is the silicate feature in the spectra of…

Solar and Stellar Astrophysics · Physics 2015-06-16 K. E. Gabanyi , L. Mosoni , A. Juhasz , P. Abraham , Th. Ratzka , N. Sipos , R. van Boekel , W. Jaffe

We present synthetic optical spectra in the range 640-930 nm of a sample of field L dwarfs and the brown dwarf GL229B. Our computations show that Li, Na, K, Rb, and Cs govern the spectra of these objects, with Na and K contributing…

Astrophysics · Physics 2007-05-23 Ya. Pavlenko , M. R. Zapatero Osorio , R. Rebolo
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