Search Publications
Variability and Jet Activity in the YSO MHO 3252 Y3 in Serpens South
Hodapp, Klaus W.; Chini, Rolf
The infrared young stellar outflow source MHO 3252 Y3 in the Serpens South star-forming region was found to be variable. The available photometric data can be fitted with a double-peaked light curve with a period of 904 days. Color variations are consistent with variable extinction with a flatter wavelength dependence than interstellar extinction,…
A Solar Eruption with Relatively Strong Geoeffectiveness Originating from Active Region Peripheral Diffusive Polarities
Wang, Rui; Liu, Ying D.; Hu, Huidong +1 more
We report the observations of a moderate but relatively intense geoeffective solar eruption on 2015 November 4 from the peripheral diffusive polarities of active region 12443. We use space-borne Solar Dynamics Observatory and ACE observations. EUV images identified a helical pattern along a filament channel, and we regard this channel as flux-rope…
The Intricate Structure of HH 508, the Brightest Microjet in the Orion Nebula
Kim, Jinyoung Serena; Close, Laird M.; Males, Jared R. +2 more
We present Magellan adaptive optics Hα imaging of HH 508, which has the highest surface brightness among protostellar jets in the Orion Nebula. We find that HH 508 actually has a shorter component to the west, and a longer and knotty component to the east. The east component has a kink at 0.″3 from the jet-driving star θ 1 Ori B2
Observing Galaxy Mergers at the Epoch of Reionization
Kaurov, Alexander A.; Chaikin, Evgenii A.; Tyulneva, Nadezda V.
The galaxies with photometric redshifts observed in a close angular proximity might be either projection coincidences, strongly lensed images of the same galaxy, or separate galaxies that are in a stage of merging. We search for the groups of galaxies in the Hubble Ultra Deep Field (HUDF09) in z ∼ 7 and z ∼ 8 drop-out samples. We find no close pai…
A Spatially Resolved Study of the GRB 020903 Host Galaxy
Levesque, Emily M.; Thorp, Mallory D.
GRB 020903 is a long-duration gamma-ray burst with a host galaxy close enough and extended enough for spatially resolved observations, making it one of less than a dozen GRBs where such host studies are possible. GRB 020903 lies in a galaxy host complex that appears to consist of four interacting components. Here we present the results of spatiall…
Velocity-resolved [O I] 63 µm Emission in the HD 50138 Circumstellar Disk
de Wit, W. -J.; Güsten, R.; Wiesemeyer, H. +5 more
HD 50138 is one of the brightest B[e] stars and is located at a distance of ∼380 pc with strong infrared excess. The star was observed in [O I] 63 µm and [C II] 158 µm with high velocity resolution with upGREAT on SOFIA. The velocity-resolved [O I] emission provides evidence for a large gas disk, ∼760 au in size, around HD 50138. Where…
High-resolution Observations of Cen A: Yellow and Red Supergiants in a Region of Jet-induced Star Formation?
Nishiyama, S.; Labadie, L.; Britzen, S. +5 more
We present the analysis of near-infrared (NIR), adaptive optics Subaru and archived HST imaging data of a region near the northern middle lobe of the Centaurus A (Cen A) jet, at a distance of ∼15 kpc northeast from the center of NGC5128. Low-pass filtering of the NIR images reveals a strong—> 3σ above the background mean—signal at the expected …
SOFIA/FORCAST Observations of the Luminous Blue Variable Candidates MN 90 and HD 168625
Smith, Nathan; Gehrz, Robert D.; Shenoy, Dinesh +1 more
We present Stratospheric Observatory for Infrared Astronomy (SOFIA)/Faint Object infraRed CAmera for the SOFIA Telescope (FORCAST) imaging of the circumstellar dust shells surrounding the luminous blue variable candidates MN 90 and HD 168625 to quantify the mineral abundances of the dust and to constrain the evolutionary state of these objects. Ou…
Limits on the Contribution of Endogenic Radiolysis to the Presence of Molecular Oxygen in Comet 67P/Churyumov-Gerasimenko
Mousis, Olivier; Bouquet, Alexis; Nicolaou, Georgios +6 more
Radiolytic production has been proposed as a potential source for the molecular oxygen observed in comet 67P/Churyumov-Gerasimenko. Radiolysis can be exogenic or endogenic, the latter due to radionuclides present in the dust constitutive of the comet nucleus. We investigated the possibility of forming a significant amount of molecular oxygen throu…
KIC 2568888: To Be or Not to Be a Binary
García, R. A.; De Ridder, J.; Mints, A. +4 more
In cases where both components of a binary system show oscillations, asteroseismology has been proposed as a method to identify the system. For KIC 2568888, observed with Kepler, we detect oscillation modes for two red giants in a single power-density spectrum. Through an asteroseismic study we investigate if the stars have similar properties, whi…