Search Publications
Hubble Space Telescope Emission Line Galaxies at z ~ 2: The Lyα Escape Fraction
Schneider, Donald P.; Blanc, Guillermo A.; Gronwall, Caryl +8 more
We compare the Hβ line strengths of 1.90 < z < 2.35 star-forming galaxies observed with the near-IR grism of the Hubble Space Telescope with ground-based measurements of Lyα from the HETDEX Pilot Survey and narrow-band imaging. By examining the line ratios of 73 galaxies, we show that most star-forming systems at this epoch have a Lyα escape…
A Search for Companions to Brown Dwarfs in the Taurus and Chamaeleon Star-Forming Regions
Todorov, K. O.; Luhman, K. L.; Konopacky, Q. M. +5 more
We have used WFPC2 on board the Hubble Space Telescope to obtain images of 47 members of the Taurus and Chamaeleon I star-forming regions that have spectral types of M6-L0 (M ~ 0.01-0.1 M ⊙). An additional late-type member of Taurus, FU Tau (M7.25+M9.25), was also observed with adaptive optics at Keck Observatory. In these images, we ha…
Observational Studies on the Near-infrared Unidentified Emission Bands in Galactic H II Regions
Onaka, Takashi; Sakon, Itsuki; Shimonishi, Takashi +4 more
Using a large collection of near-infrared spectra (2.5-5.4 µm) of Galactic H II regions and H II region-like objects, we perform a systematic investigation of astronomical polycyclic aromatic hydrocarbon (PAH) features. Thirty-six objects were observed using the infrared camera on board the AKARI satellite as a part of a director's time prog…
The Spatially Resolved Bipolar Nebula of Sakurai's Object
Hinkle, Kenneth H.; Joyce, Richard R.
Sakurai's object (V4334 Sgr), the final flash object discovered in the mid-1990s, underwent rapid cooling during the first decade of the 21st century becoming as faint as K ~ 25. This stage of evolution has ceased. Between observations in 2010 September and 2013 April V4334 Sgr brightened >2 mag to K = 14.2 and the effective temperature increas…
Not-so-simple Stellar Populations in the Intermediate-age Large Magellanic Cloud Star Clusters NGC 1831 and NGC 1868
Deng, Licai; de Grijs, Richard; Li, Chengyuan
Using a combination of high-resolution Hubble Space Telescope/Wide-Field and Planetary Camera-2 observations, we explore the physical properties of the stellar populations in two intermediate-age star clusters, NGC 1831 and NGC 1868, in the Large Magellanic Cloud based on their color-magnitude diagrams. We show that both clusters exhibit extended …
High-resolution Submillimeter and Near-infrared Studies of the Transition Disk around Sz 91
Henning, Thomas; Terada, Hiroshi; Usuda, Tomonori +55 more
To reveal the structures of a transition disk around a young stellar object in Lupus, Sz 91 , we have performed aperture synthesis 345 GHz continuum and CO(3-2) observations with the Submillimeter Array (~1''-3'' resolution) and high-resolution imaging of polarized intensity at the Ks -band using the HiCIAO instrument on the Subaru Tele…
X-Ray and γ-Ray Studies of the Millisecond Pulsar and Possible X-Ray Binary/Radio Pulsar Transition Object PSR J1723-2837
Esposito, Paolo; Bogdanov, Slavko; McLaughlin, Maura A. +3 more
We present X-ray observations of the "redback" eclipsing radio millisecond pulsar (MSP) and candidate radio pulsar/X-ray binary transition object PSR J1723-2837. The X-ray emission from the system is predominantly non-thermal and exhibits pronounced variability as a function of orbital phase, with a factor of ~2 reduction in brightness around supe…
The Comparison of Physical Properties Derived from Gas and Dust in a Massive Star-forming Region
Ginsburg, Adam; Battersby, Cara; Bally, John +3 more
We explore the relationship between gas and dust in a massive star-forming region by comparing the physical properties derived from each. We compare the temperatures and column densities in a massive star-forming Infrared Dark Cloud (G32.02+0.05), which shows a range of evolutionary states, from quiescent to active. The gas properties were derived…
Herschel Evidence for Disk Flattening or Gas Depletion in Transitional Disks
Dent, W. R. F.; Woitke, P.; Kamp, I. +6 more
Transitional disks are protoplanetary disks characterized by reduced near- and mid-infrared emission, with respect to full disks. This characteristic spectral energy distribution indicates the presence of an optically thin inner cavity within the dust disk believed to mark the disappearance of the primordial massive disk. We present new Herschel S…
The Tip of the Red Giant Branch Distance to the Perfect Spiral Galaxy M74 Hosting Three Core-collapse Supernovae
Lee, Myung Gyoon; Jang, In Sung
M74 (NGC 628) is a famous face-on spiral galaxy, hosting three core-collapse supernovae (SNe): SN Ic 2002ap, SN II-P 2003gd, and SN II-P 2013ej. However, its distance is not well known. We present a distance estimation for this galaxy based on the Tip of the Red Giant Branch (TRGB) method. We obtain photometry of the resolved stars in the arm-free…