Search Publications
Pursuing the Planet-Debris Disk Connection: Analysis of Upper Limits from the Anglo-Australian Planet Search
Wittenmyer, Robert A.; Marshall, Jonathan P.
Solid material in protoplanetary disks will suffer one of two fates after the epoch of planet formation; either being bound up into planetary bodies, or remaining in smaller planetesimals to be ground into dust. These end states are identified through detection of sub-stellar companions by periodic radial velocity (or transit) variations of the st…
Cepheid Variables in the Maser-host Galaxy NGC 4258
Macri, Lucas M.; Hoffmann, Samantha L.
We present results of a ground-based survey for Cepheid variables in NGC 4258. This galaxy plays a key role in the Extragalactic Distance Scale due to its very precise and accurate distance determination via very long baseline interferometry observations of water masers. We imaged two fields within this galaxy using the Gemini North telescope and …
Metallicity Distribution Functions of Four Local Group Dwarf Galaxies
Holtzman, Jon; Anthony-Twarog, Barbara J.; Saha, Abhijit +1 more
We present stellar metallicities in Leo I, Leo II, IC 1613, and Phoenix dwarf galaxies derived from medium (F390M) and broad (F555W, F814W) band photometry using the Wide Field Camera 3 instrument on board the Hubble Space Telescope. We measured metallicity distribution functions (MDFs) in two ways, (1) matching stars to isochrones in color-color …
An Emerging Wolf-Rayet Massive Star Cluster in NGC 4449
Johnson, Kelsey E.; Indebetouw, Rémy; Reines, Amy E. +1 more
We present a panchromatic investigation of the partially embedded, emerging massive cluster Source 26 (=S26) in NGC 4449 with optical spectra obtained at Apache Point Observatory and archival Hubble, Spitzer, and Herschel 5 Space Telescope images. First identified as a radio continuum source with a thermal component due to ionized mater…
The Optical Wind Line Variability of η Carinae During the 2009.0 Event
Gull, T. R.; Gies, D. R.; Richardson, N. D. +2 more
We report on high-resolution spectroscopy of the 2009.0 spectroscopic event of η Carinae collected via SMARTS observations using the CTIO 1.5 m telescope and echelle spectrograph. Our observations were made almost every night over a two-month interval around the photometric minimum of η Car associated with the periastron passage of a hot companion…
Discovery of Nine Extended Ionized Gas Clouds in a z = 0.4 Cluster
Gu, Liyi; Koyama, Yusei; Kodama, Tadayuki +4 more
From deep Hα imaging data of Suprime-Cam/Subaru, we discovered nine extended ionized gas clouds (EIG) around galaxies in the Abell 851 cluster (A851) at z = 0.4. We surveyed a 30 × 25 arcmin region, and the EIGs were found only near the cluster center (\lt 2.3 arcmin ∼ 750 kpc). The parent galaxies of the EIGs are star-forming or post-starburst ga…
Pan-Chromatic Observations of the Remarkable Nova Large Magellanic Cloud 2012
Walter, Frederick M.; Drake, Jeremy J.; Woodward, Charles E. +9 more
We present the results of an intensive multiwavelength campaign on nova LMC 2012. This nova evolved very rapidly in all observed wavelengths. The time to fall two magnitudes in the V band was only 2 days. In X-rays the super soft phase began 13 ± 5 days after discovery and ended around day 50 after discovery. During the super soft phase, the Swift…
An X-Ray Flare from 47 Cas
Karmakar, Subhajeet; Pandey, Jeewan C.
Using XMM-Newton observations, we investigate properties of a flare from the very active but poorly known stellar system 47 Cas. The luminosity at the peak of the flare is found to be 3.54 × 1030 erg {{s}-1}, which is ∼2 times higher than that at a quiescent state. The quiescent state corona of 47 Cas can be represented by tw…
Stellar Populations and the Star Formation Histories of LSB Galaxies. V. WFC3 Color-Magnitude Diagrams
Schombert, James; McGaugh, Stacy
We present WFC3 observations of three low surface brightness (LSB) galaxies from the Schombert et al. LSB catalog that are within 11 Mpc of the Milky Way. Deep imaging at F336W, F555W, and F814W allow the construction of the V - I color-magnitude diagrams (CMD) to MI = -2. Overall 1869, 465, and 501 stellar sources are identified in the…
A Catalog of Point Sources Toward NGC 1333
Rebull, L. M.
I present a catalog of point-source objects toward NGC 1333, resolving a wide variety of confusion about source names (and occasionally positions) in the literature. I incorporate data from optical to radio wavelengths, but focus most of the effort on being complete and accurate from J (1.25 µm) to 24 µm. The catalog encompasses 52^\ci…