Search Publications
Tadpole Galaxies in the Hubble Ultra Deep Field
Elmegreen, Bruce G.; Elmegreen, Debra Meloy
Tadpole galaxies have a head-tail shape with a large clump of star formation at the head and a diffuse tail or streak of stars off to one side. We measured the head and tail masses, ages, surface brightnesses, and sizes for 66 tadpoles in the Hubble Ultra Deep Field (UDF) and looked at the distribution of neighbor densities and tadpole orientation…
Testing adiabatic contraction of dark matter in fossil group candidates
Arnaud, M.; Pratt, G. W.; Zibetti, S. +3 more
We present deep XMM-Newton observations and ESO WFI optical imaging of two X-ray-selected fossil group candidates, RXC J0216.7-4749 and RXC J2315.7-0222. Using the X-ray data, we derive total mass profiles under the hydrostatic equilibrium assumption. The central regions of RXC J0216.7-4749 are found to be dominated by an X-ray bright AGN, and alt…
A sample of [C II] clouds tracing dense clouds in weak FUV fields observed by Herschel
Li, D.; Goldsmith, P. F.; Langer, W. D. +3 more
The [C ii] fine-structure line at 158 µm is an excellent tracer of the warm diffuse gas in the ISM and the interfaces between molecular clouds and their surrounding atomic and ionized envelopes. Here we present the initial results from Galactic observations of terahertz C+ (GOT C+), a Herschel key project devoted to studying the […
Observing Supernova 1987A with the Refurbished Hubble Space Telescope
Smith, Nathan; Pun, Chun S. J.; France, Kevin +18 more
Observations with the Hubble Space Telescope (HST), conducted since 1990, now offer an unprecedented glimpse into fast astrophysical shocks in the young remnant of supernova 1987A. Comparing observations taken in 2010 with the use of the refurbished instruments on HST with data taken in 2004, just before the Space Telescope Imaging Spectrograph fa…
Investigating gully flow emplacement mechanisms using apex slopes
McEwen, Alfred S.; Pelletier, Jon D.; Kolb, Kelly Jean
The origin of the martian gullies has been much debated since their discovery by the Mars Orbiter Camera (MOC, Malin, M.C., Edgett, K.S. [2000]. Science 288, 2330-2335). Several previous studies have looked at slope gradients in and around gullies, but none have used Digital Elevation Models (DEMs) from the High Resolution Imaging Science Experime…
The Anomalous Accretion Disk of the Cataclysmic Variable RW Sextantis
Szkody, Paula; Sion, Edward M.; Godon, Patrick +2 more
Synthetic spectra covering the wavelength range 900-3000 Å provide an accurate fit, established by a χ2 ν analysis, to a combined observed spectrum of RW Sextantis. Two separately calibrated distances to the system establish the synthetic spectrum comparison on an absolute flux basis but with two alternative scaling factors, …
North-south asymmetry of the location of the heliospheric current sheet revisited
Balogh, A.; ErdőS, G.
The possible latitudinal offset of the location of the heliospheric current sheet (HCS) is an important question, since it has impact on the understanding of various phenomena including the solar dynamo and the modulation of cosmic rays. In the declining phase of the previous, 22nd solar cycle, in 1993, a southward displacement of the HCS by 10° w…
Spin-Down of the Long-Period Accreting Pulsar 4U 2206+54
Patel, Sandeep K.; Finger, Mark H.; Wilson-Hodge, Colleen A. +1 more
4U 2206+54 is a high-mass X-ray binary which has been suspected to contain a neutron star accreting from the wind of its companion, BD +53° 2790. Reig et al. have recently detected 5560 s period pulsations in both Rossi X-ray Timing Explorer (RXTE) and International Gamma-ray Astrophysics Laboratory observations which they conclude are due to the …
Shape and obliquity effects on the thermal evolution of the Rosetta target 67P/Churyumov-Gerasimenko cometary nucleus
Lasue, J.; Coradini, A.; De Sanctis, M. C. +3 more
This work is dedicated to the application to 67P/Churyumov-Gerasimenko of a new quasi-3D approach for non-spherically shaped comet nuclei with the aim to interpret the current activity of the comet in terms of initial characteristics and to predict shape and internal stratification evolution of the nucleus. The model is applied to differently shap…
Spectro-photometric close pairs in GOODS-S: major and minor companions of intermediate-mass galaxies
Pérez-González, P. G.; López-Sanjuan, C.; Gallego, J. +3 more
Aims: Recent work has shown that major mergers of disc galaxies can only account for 20% of the growth of the galaxy red sequence between z = 1 and z = 0. Our goal here is to provide merger frequencies that encompass both major and minor mergers, derived from close pair statistics. We aim to show that reliable close pair statistics can be der…