Search Publications
Missions
Journals
Publication Years
Empirically Constrained Color-Temperature Relations. I. BV(RI)C
VandenBerg, Don A.; Clem, James L.
This investigation presents a set of transformations to Johnson B-V, Cousins V-R, and Cousins V-I, as well as bolometric corrections to V, for [Fe/H]=-3, -2, -1, -0.5, 0.0, and +0.3 and, in each case, values of logg from -0.5 to 5.0 for 3000 K<=Teff<=5500 K and from 2.0 to 5.0 for 6000 K<=Teff<=40,000 K. These tra…
Hα Spectroscopy of Galaxies at z > 2: Kinematics and Star Formation
Pettini, Max; Erb, Dawn K.; Shapley, Alice E. +5 more
We present near-infrared spectroscopy of Hα emission lines in a sample of 16 star-forming galaxies at redshifts 2.0<z<2.6. Our targets are drawn from a large sample of galaxies photometrically selected and spectroscopically confirmed to lie in this redshift range. We have obtained this large sample with an extension of the broadband Un<…
Theories of solar eruptions: a review
Lin, J.; Baliunas, S. L.; Soon, W.
This review highlights current theoretical research on eruptive phenomena in the solar atmosphere. We start by looking back upon the early theories and their development. Any theory and model of solar eruptions must explain two key aspects of eruption physics. The first aspect concerns the original cause of the eruption and the second pertains to …
A Hubble Space Telescope Survey of Extended [O III] λ5007 Emission in a Far-Infrared Selected Sample of Seyfert Galaxies: Observations
Hutchings, J. B.; Schmitt, H. R.; Donley, J. L. +2 more
We present a Hubble Space Telescope (HST) survey of extended [O III] emission for a sample of 60 Seyfert galaxies (22 Seyfert 1 galaxies and 38 Seyfert 2 galaxies), selected based on their far-infrared properties. The observations for 42 of these galaxies were done in a snapshot survey with WFPC2. The remaining 18 were obtained from the HST archiv…
New Members of the TW Hydrae Association, β Pictoris Moving Group, and Tucana/Horologium Association
Zuckerman, B.; Song, Inseok; Bessell, M. S.
We have identified five new members of the TW Hydrae association (TWA), 11 new members of the β Pic moving group, and 11 new Tucana/Horologium association members. These are the three youngest (<~30 Myr) known kinematic stellar groups near the Earth. Newly identified β Pic group members are located mostly in the northern hemisphere, and they ha…
Solar active regions: SOHO/CDS and TRACE observations of quiescent coronal loops
Mason, H. E.; Del Zanna, G.
This study focuses on the diagnostic capabilities of the TRACE and SOHO-CDS instruments to describe the physical characteristics of quiescent solar active regions. In particular we concentrate on the 1 MK loops, best seen in the TRACE EUV 173 Å passband. These are high-lying structures which can remain stable over timescales of hours to days. We p…
The age, life expectancy, and space density of Post Common Envelope Binaries
Gänsicke, B. T.; Schreiber, M. R.
We present a sample of 30 well observed Post Common Envelope Binaries (PCEBs). Deriving the cooling age of the white dwarfs, we show that the PCEB population is dominated by young systems. Having calculated the orbital evolution of the systems under the assumption of two different prescriptions for the angular momentum loss, we find that most of t…
Star cluster formation and disruption time-scales - I. An empirical determination of the disruption time of star clusters in four galaxies
Lamers, H. J. G. L. M.; Boutloukos, S. G.
We have derived the disruption times of star clusters from cluster samples of four galaxies, M51, M33, the Small Magellanic Cloud (SMC) and the solar neighbourhood. If the disruption time of clusters in a galaxy depends only on their initial mass as tdis(yr) =t4dis(Mcl/104 Msolar)
Hubble Space Telescope Observations of Binary Very Low Mass Stars and Brown Dwarfs
Kirkpatrick, J. Davy; Burgasser, Adam J.; Gizis, John E. +4 more
We present analysis of Hubble Space Telescope (HST) images of 82 nearby field late M and L dwarfs. We resolve 13 of these systems into double M/L dwarf systems and identify an additional possible binary. Combined with previous observations of 20 L dwarfs, we derive an observed binary fraction for ultracool dwarfs of 17+4-3%, …
Multiwavelength Observations of Flares on AD Leonis
Hawley, Suzanne L.; Valenti, Jeff A.; Johns-Krull, Christopher M. +9 more
We report results from a multiwavelength observing campaign conducted during 2000 March on the flare star AD Leo. Simultaneous data were obtained from several ground- and space-based observatories, including observations of eight sizable flares. We discuss the correlation of line and continuum emission in the optical and ultraviolet wavelength reg…