Search Publications
XMM-Newton Observations of Luminous Sources in Nearby Galaxies NGC 4395, NGC 4736, and NGC 4258
Balman, S.; Akyuz, A.; Sonbas, E. +3 more
We present the results of a study of non-nuclear discrete sources in a sample of three nearby spiral galaxies (NGC 4395, NGC 4736, and NGC 4258) based on XMM-Newton archival data supplemented with Chandra data for spectral and timing analyses. A total of 75 X-ray sources have been detected within the D 25 regions of the target galaxies.…
Investigating the Core Morphology-Seyfert Class Relationship with Hubble Space Telescope Archival Images of Local Seyfert Galaxies
Kim, Hwihyun; Rutkowski, M. J.; Windhorst, R. A. +2 more
The unified model of active galactic nuclei (AGNs) has provided a successful explanation for the observed diversity of AGNs in the local universe. However, recent analysis of multi-wavelength spectral and image data suggests that the unified model is only a partial theory of AGNs, and may need to be augmented to remain consistent with all observat…
Far-ultraviolet Spectroscopy of the Nova-like Variable KQ Monocerotis: A New SW Sextantis Star?
Bond, Howard E.; Sion, Edward M.; Wolfe, Aaron
New optical spectra obtained with the SMARTS 1.5 m telescope and archival International Ultraviolet Explorer (IUE) far-ultraviolet (FUV) spectra of the nova-like variable KQ Mon are discussed. The optical spectra reveal Balmer lines in absorption as well as He I absorption superposed on a blue continuum. The 2011 optical spectrum is similar to the…
Relative Photometry of HAT-P-1b Occultations
Winn, Joshua N.; Gilliland, Ronald L.; Bakos, Gáspár Á. +4 more
We present Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph observations of two occultations of the transiting exoplanet HAT-P-1b. By measuring the planet to star flux ratio near opposition, we constrain the geometric albedo of the planet, which is strongly linked to its atmospheric temperature gradient. An advantage of HAT-P-1 as…
Efficient Selection and Classification of Infrared Excess Emission Stars Based on AKARI and 2MASS Data
Zeng Li, Jin; Rector, Travis A.; Huang, Ya Fang +1 more
The selection of young stellar objects (YSOs) based on excess emission in the infrared is easily contaminated by post-main-sequence stars and various types of emission line stars with similar properties. We define in this paper stringent criteria for an efficient selection and classification of stellar sources with infrared excess emission based o…
Twenty-five Subarcsecond Binaries Discovered by Lunar Occultations
Cusano, F.; Richichi, A.; Fors, O. +1 more
We report on 25 subarcsecond binaries, detected for the first time by means of lunar occultations in the near-infrared (near-IR) as part of a long-term program using the ISAAC instrument at the ESO Very Large Telescope. The primaries have magnitudes in the range K = 3.8-10.4, and the companions in the range K = 6.4-12.1. The magnitude differences …
Filter-induced Bias in Lyα Emitter Surveys: A Comparison between Standard and Tunable Filters. Gran Telescopio Canarias Preliminary Results
Cepa, J.; Bongiovanni, A.; González-Serrano, J. I. +4 more
Lyα emitter (LAE) surveys have successfully used the excess in a narrowband filter compared to a nearby broadband image to find candidates. However, the odd spectral energy distribution (SED) of LAEs combined with the instrumental profile has important effects on the properties of the candidate samples extracted from these surveys. We investigate …
An STIS Atlas of Ca II Triplet Absorption Line Kinematics in Galactic Nuclei
Axon, D.; Batcheldor, D.; Valluri, M. +2 more
The relations observed between supermassive black holes and their host galaxies suggest a fundamental link in the processes that cause these two objects to evolve. A more comprehensive understanding of these relations could be gained by increasing the number of supermassive black hole mass (M •) measurements. This can be achieved, in pa…
Uncloaking Globular Clusters in the Inner Galaxy
Minniti, Dante; Mateo, Mario; von Braun, Kaspar +4 more
Extensive photometric studies of the globular clusters located toward the center of the Milky Way have been historically neglected. The presence of patchy differential reddening in front of these clusters has proven to be a significant obstacle to their detailed study. We present here a well defined and reasonably homogeneous photometric database …
The Solar Neighborhood. XXVIII. The Multiplicity Fraction of Nearby Stars from 5 to 70 AU and the Brown Dwarf Desert around M Dwarfs
Krist, John E.; Golimowski, David A.; Henry, Todd J. +2 more
We report on our analysis of Hubble Space Telescope/NICMOS snapshot high-resolution images of 255 stars in 201 systems within ~10 pc of the Sun. Photometry was obtained through filters F110W, F180M, F207M, and F222M using NICMOS Camera 2. These filters were selected to permit clear identification of cool brown dwarfs through methane contrast imagi…