Search Publications
SOFIA Mid-infrared Imaging1 and CSO Submillimeter Polarimetry Observations of G034.43+00.24 MM1
Gehrz, R. D.; Vaillancourt, John E.; Shenoy, Dinesh +3 more
We present 11.1 to 37.1 µm imaging observations of the very dense molecular cloud core MM1 in G034.43+00.24 using FORCAST on SOFIA and submillimeter (submm) polarimetry using SHARP on the Caltech Submillimeter Observatory. We find that at the spatial resolution of SOFIA, the point-spread function (PSF) of MM1 is consistent with being a singl…
Detection of H I in Emission in the LYα Emitting Galaxy Haro 11
Cannon, John M.; Hayes, Matthew; Östlin, Göran +2 more
We present the first robust detection of H I 21 cm emission in the blue compact galaxy Haro 11 using the 100 m Robert C. Byrd Green Bank Telescope (GBT). Haro 11 is a luminous blue compact galaxy with emission in both Lyα and the Lyman continuum. We detect (5.1 ± 0.7 × 108) M ⊙ of H I gas at an assumed distance of 88 Mpc, mak…
A High-resolution Multiband Survey of Westerlund 2 with the Hubble Space Telescope. II. Mass Accretion in the Pre-main-sequence Population
Grebel, Eva K.; Bonanos, Alceste Z.; Sabbi, Elena +5 more
We present a detailed analysis of the pre-main-sequence (PMS) population of the young star cluster Westerlund 2 (Wd2), the central ionizing cluster of the H II region RCW 49, using data from a high-resolution multiband survey with the Hubble Space Telescope. The data were acquired with the Advanced Camera for Surveys in the F555W, F814W, and F658N…
GW Librae: Still Hot Eight Years Post-outburst
Szkody, Paula; Sion, Edward M.; Gänsicke, Boris T. +8 more
We report continued Hubble Space Telescope (HST) ultraviolet spectra and ground-based optical photometry and spectroscopy of GW Librae eight years after its largest known dwarf nova outburst in 2007. This represents the longest cooling timescale measured for any dwarf nova. The spectra reveal that the white dwarf still remains about 3000 K hotter …
The Time Evolution of HH 1 from Four Epochs of HST Images
Bally, J.; Raga, A. C.; Esquivel, A. +1 more
We present an analysis of four epochs of Hα and [S II] λλ 6716/6731 Hubble Space Telescope (HST) images of HH 1. For determining proper motions, we explore a new method based on the analysis of spatially degraded images obtained convolving the images with wavelet functions of chosen widths. With this procedure, we are able to generate maps of prop…
A Global Astrometric Solution for Pan-STARRS Referenced to ICRF2
Frouard, J.; Dorland, B. N.; Makarov, V. V. +13 more
We describe the development and application of a Global Astrometric Solution (GAS) to the problem of Pan-STARRS1 (PS1) astrometry. Current PS1 astrometry is based on differential astrometric measurements using 2MASS reference stars, and thus PS1 astrometry inherits the errors of the 2MASS catalog. The GAS, based on a single, least-squares adjustme…
Near-infrared Circular and Linear Polarimetry of Monoceros R2
Kwon, Jungmi; Nagata, Tetsuya; Tamura, Motohide +2 more
We have conducted simultaneous JHK s -band imaging circular and linear polarimetry of the Monoceros R2 (Mon R2) cluster. We present results from deep and wide near-infrared linear polarimetry of the Mon R2 region. Prominent and extended polarized nebulosities over the Mon R2 field are revisited, and an infrared reflection nebula associ…
The Kinematics of the Nebular Shells Around Low Mass Progenitors of PNe with Low Metallicity
Richer, Michael G.; López, José Alberto; Pereyra, Margarita
We analyze the internal kinematics of 26 planetary nebulae (PNe) with low metallicity that appear to derive from progenitor stars of the lowest masses, including the halo PN population. Based upon spatially resolved, long-slit, echelle spectroscopy drawn from the San Pedro Mártir Kinematic Catalog of PNe, we characterize the kinematics of these PN…
The Putative Old, Nearby Cluster Lodén 1 Does Not Exist
Wright, Jason T.; Curtis, Jason L.; Han, Eunkyu
Astronomers have access to precious few nearby, middle-aged benchmark star clusters. Within 500 pc, there are only NGC 752 and Ruprecht 147 (R147) at 1.5 and 3 Gyr, respectively. The Database for Galactic Open Clusters (WEBDA) also lists Lodén 1 as a 2 Gyr cluster at a distance of 360 pc. If this is true, Lodén 1 could become a useful benchmark cl…
Cool Subdwarf Investigations. III. Dynamical Masses of Low-metallicity Subdwarfs
Nelan, Edmund P.; Henry, Todd J.; Wasserman, Lawrence H. +2 more
We report dynamical mass measurements for the components of the previously known double-lined spectroscopic subdwarfs G 006-026 B and C using the Fine Guidance Sensors on the Hubble Space Telescope. To build the empirical mass-luminosity relation for low-metallicity subdwarfs, we collect four other subdwarf systems with dynamical masses that we co…