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Related papers: The age of cataclysmic variables: a kinematical st…

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We simulated the long-term collisional depletion of debris disks around solar-type (G2V) stars with our code. The numerical results were supplemented by, and interpreted through, a new analytic model. A few general scaling rules for the…

Astrophysics · Physics 2009-11-13 Torsten Löhne , Alexander V. Krivov , Jens Rodmann

In this Letter, we analyse the distributions of stellar ages in Giant Molecular Clouds (GMCs) in spiral arms, inter-arm spurs, and at large galactic radii, where the spiral arms are relatively weak. We use the results of numerical…

Astrophysics of Galaxies · Physics 2015-06-17 C. L. Dobbs , J. E. Pringle , T. Naylor

We aim at a detailed description of the kinematic properties of the old, (several Gyrs) late-type CO-absorption star population among the Galactic centre (GC) cluster stars. We applied AO-assisted, near-infrared imaging and integral-field…

We present time-resolved optical spectroscopy and photometry of four relatively bright (V~14.0-15.5) long-period cataclysmic variables (CVs) discovered in the Hamburg Quasar Survey: HS0139+0559, HS0229+8016, HS0506+7725 and HS0642+5049.…

We present a statistical analysis of the ultraviolet emission lines of cataclysmic variables (CVs) based on $\approx 430$ ultraviolet spectra of 20 sources extracted from the International Ultraviolet Explorer Uniform Low Dispersion…

Astrophysics · Physics 2009-10-28 Christopher W. Mauche , Y. Paul Lee , Timothy R. Kallman

The velocity dispersion of stars in the solar neighbourhood thin disc increases with time after star formation. Nordstrom et al. (2004) is the most recent observational attempt to constrain the age-velocity dispersion relation. They fitted…

Astrophysics · Physics 2009-11-13 G. M. Seabroke , G. Gilmore

Circumbinary (CB) disks have been proposed as a mechanism to extract orbital angular momentum from cataclysmic variables (CVs) during their evolution. As proposed by Taam & Spruit, these disks extend outwards to several a.u. and should be…

Astrophysics · Physics 2009-11-10 K. E. Belle , N. Sanghi , S. B. Howell , J. B. Holberg , P. T. Williams

We present a search for excess mid-IR emission due to circumbinary material in the orbital plane of cataclysmic variables (CVs). Our motivation stems from the fact that the strong braking exerted by a circumbinary (CB) disc on the binary…

Astrophysics · Physics 2009-11-10 G. Dubus , R. Campbell , B. Kern , R. E. Taam , H. C. Spruit

Between 40$\%$ and 80$\%$ of cataclysmic variables (CVs) are expected to have evolved past the period-minimum and contain a degenerate donor. However, observational surveys for CVs have only been able to detect a few of these highly evolved…

Solar and Stellar Astrophysics · Physics 2026-03-04 Daniela Muñoz-Giraldo , Beate Stelzer , Axel Schwope , Santiago Hernández-Díaz , Scott F. Anderson , Sebastian Demasi

Open star clusters from the MWSC (Milky Way Star Clusters) catalogue have been used to determine the Galactic rotation parameters. The circular rotation velocity of the solar neighborhood around the Galactic center has been found from data…

Astrophysics of Galaxies · Physics 2016-09-30 V. V. Bobylev , A. T. Bajkova , K. S. Shirokova

Currently available data on the field of velocities Vr, Vl, Vb for open star clusters are used to perform a kinematic analysis of various samples that differ by heliocentric distance, age, and membership in individual structures (the Orion,…

Astrophysics · Physics 2008-11-26 V. V. Bobylev , A. T. Bajkova , S. V. Lebedeva

We present the age-velocity dispersion relation (AVR) in three dimensions in the solar neighbourhood using 3,564 commonly observed sub-giant/red-giant branch stars selected from LAMOST, which gives the age and radial velocity, and…

Astrophysics of Galaxies · Physics 2018-01-31 Jincheng Yu , Chao Liu

From a large observing campaign, we found that nearly all non- or weakly magnetic cataclysmic variables (CVs) in the orbital period range between 2.8 and 4 hours are of SW Sex type and as such experience very high mass transfer rates. The…

Solar and Stellar Astrophysics · Physics 2013-03-13 Linda Schmidtobreick , Claus Tappert

We use high-resolution near-infrared spectroscopy from Keck Observatory to measure the stellar velocity dispersions of 19 super star clusters (SSCs) in the nuclear starburst of M82. The clusters have ages on the order of 10 Myr, which is…

Astrophysics · Physics 2009-06-23 Nate McCrady , James R. Graham

We present a study of the relationship between galactic kinematics, flare rates, chromospheric activity, and rotation periods for a volume-complete, nearly all-sky sample of 219 single stars within 15 parsecs and with masses between…

Solar and Stellar Astrophysics · Physics 2022-08-31 Amber A. Medina , Jennifer G. Winters , Jonathan M. Irwin , David Charbonneau

The evolution of Cataclysmic Variables (CVs) is driven by period-changes ($\dot{P}$), for which the long-venerable consensus is the Magnetic Braking Model (MBM). The MBM has its only distinctive assumption being a power-law `recipe'…

Solar and Stellar Astrophysics · Physics 2024-04-22 Bradley E. Schaefer

Continuing our work from Paper I (Southworth et al., 2006) we present medium-resolution spectroscopy and broad-band photometry of seven cataclysmic variables (CVs) discovered by the SDSS. For six of these objects we derive accurate orbital…

We show that the well-known discrepancy between the radial dependence of the Galactic cosmic ray (CR) nucleon distribution, as inferred most recently from EGRET observations of diffuse gamma-rays above 100 MeV, and of the most likely CR…

Astrophysics · Physics 2009-11-07 D. Breitschwerdt , V. A. Dogiel , H. J. Voelk

A sample of Cataclysmic Variables (CVs) is presented including spectroscopically identified 380 spectra of 245 objects, of which 58 CV candidates are new discoveries. The BaggingTopPush and the Random Forest algorithms are applied to the…

Solar and Stellar Astrophysics · Physics 2020-01-15 Wen Hou , A-Li Luo , Yin-Bi Li , Li Qin

We have developed a spectrum synthesis method for modeling the UV emission from the accretion disk from cataclysmic variables (CVs). The disk is separated into concentric rings, with an internal structure from the Wade & Hubeny…

Solar and Stellar Astrophysics · Physics 2015-05-28 Raul E. Puebla , Marcos P. Diaz , D. John Hillier , Ivan Hubeny