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X-Ray Studies of the Extended TeV Gamma-Ray Source VER J2019+368
Mizuno, T.; Takahashi, H.; Katsuta, J. +3 more
This article reports the results of X-ray studies of the extended TeV γ-ray source VER J2019+368. Suzaku observations conducted to examine properties of the X-ray pulsar wind nebula (PWN) around PSR J2021+3651 revealed that the western region of the X-ray PWN has a source extent of 15\prime × 10\prime with the major axis orie…
Variations between Dust and Gas in the Diffuse Interstellar Medium. II. Search for Cold Gas
Heiles, Carl; Reach, William T.; Bernard, Jean-Philippe
The content of interstellar clouds, in particular the inventory of diffuse molecular gas, remains uncertain. We identified a sample of isolated clouds, approximately 100 M⊙ in size, and used the dust content to estimate the total amount of gas. In Paper I, the total inferred gas content was found significantly larger than that seen in 2…
Toward Understanding The B[e] Phenomenon. VI. Nature and Spectral Variations of HD 85567.
Reichart, D. E.; Miroshnichenko, A. S.; Haislip, J. B. +7 more
We report the results of high-resolution (R ∼ 80,000) spectroscopic observations of the emission-line object HD 85567, which has been classified as an FS CMa type object or a pre-main-sequence star. The main goal is to put more constraints on the object’s fundamental parameters, as well as on its nature and evolutionary state. Absorption lines in …
A Closer Look at the Alpha Persei Coronal Conundrum
Ayres, Thomas R.
A ROSAT survey of the Alpha Per open cluster in 1993 detected its brightest star, the mid-F supergiant α Persei: the X-ray luminosity and spectral hardness were similar to coronally active late-type dwarf members. Later, in 2010, a Hubble Cosmic Origins Spectrograph SNAPshot of α Per found the far-ultraviolet (FUV) coronal-proxy Si IV unexpectedly…
Properties of the Closest Young Binaries. I. DF Tau’s Unequal Circumstellar Disk Evolution
Prato, L.; Schaefer, G.; Simon, M. +6 more
We present high-resolution, spatially resolved, near-infrared spectroscopy and imaging of the two components of DF Tau, a young, low-mass, visual binary in the Taurus star-forming region. With these data, we provide a more precise orbital solution for the system, determine component spectral types, radial velocity, veiling and v\sin i values, and …
Sudden Penumbral Reappearance and Umbral Motion Induced by an M7.9 Solar Flare
Yang, Jiayan; Hong, Junchao; Xu, Zhe +2 more
The sudden flare-related changes of sunspot structures have been recognized as the photospheric responses to the solar eruptions in the corona. In this study, we report two distinctive sunspots variations associated with the flare SOL2015-06-25T08:16 (M7.9). Along the flaring polarity inversion line (PIL), the originally decayed penumbra showed a …
Observations of Reconnection Flows in a Flare on the Solar Disk
Fletcher, L.; Hannah, I. G.; Jeffrey, N. L. S. +3 more
Magnetic reconnection is a well-accepted part of the theory of solar eruptive events, though the evidence is still circumstantial. Intrinsic to the reconnection picture of a solar eruptive event, particularly in the standard model for two-ribbon flares (CSHKP model), are an advective flow of magnetized plasma into the reconnection region, expansio…
H2 Fluorescence in M Dwarf Systems: A Stellar Origin
Loyd, R. O. Parke; Roberge, Aki; Kruczek, Nicholas +7 more
Observations of molecular hydrogen (H2) fluorescence are a potentially useful tool for measuring the H2 abundance in exoplanet atmospheres. This emission was previously observed in {{M}} dwarfs with planetary systems. However, low signal-to-noise prevented a conclusive determination of its origin. Possible sources include exo…
SOFIA-EXES Mid-IR Observations of [Fe II] Emission from the Extended Atmosphere of Betelgeuse
Ryde, N.; Greathouse, T. K.; Guinan, E. F. +5 more
We present a NASA-DLR SOFIA-Echelon Cross Echelle Spectrograph (EXES) and NASA Infrared Telescope Facility-Texas Echelon Cross Echelle Spectrograph (TEXES) mid-IR R≃ {{50,000}} spectral study of forbidden Fe II transitions in the early-type M supergiants, Betelgeuse (α Ori: M2 Iab) and Antares (α Sco: M1 Iab + B3 V). With EXES, we spectrally resol…
Constraints on the Progenitor of SN 2010jl and Pre-existing Hot Dust in its Surrounding Medium
Van Dyk, Schuyler D.; Filippenko, Alexei V.; Kelly, Patrick L. +6 more
A search for the progenitor of SN 2010jl, an unusually luminous core-collapse supernova of Type IIn, using pre-explosion Hubble/WFPC2 and Spitzer/IRAC images of the region, yielded upper limits on the UV and near-infrared (IR) fluxes from any candidate star. These upper limits constrain the luminosity and effective temperature of the progenitor, t…