Search Publications
Absolute Dimensions of the F-type Eclipsing Binary V2154 Cygni
Torres, Guillermo; Bright, Jane C.
We report spectroscopic observations of the 2.63 day, detached, F-type main-sequence eclipsing binary V2154 Cyg. We use our observations together with existing uvby photometric measurements to derive accurate absolute masses and radii for the stars that are good to better than 1.5%. We obtain masses of {M}1=1.269+/- 0.017 {M}⊙
SG1120-1202: Mass-quenching as Tracked by UV Emission in the Group Environment at z=0.37
Tran, Kim-Vy H.; Gonzalez, Anthony H.; Monroe, Jonathan T.
We use the Hubble Space Telescope to obtain WFC3/F390W imaging of the supergroup SG1120-1202 at z=0.37, mapping the UV emission of 138 spectroscopically confirmed members. We measure total (F390W-F814W) colors and visually classify the UV morphology of individual galaxies as “clumpy” or “smooth.” Approximately 30% of the members have pockets of UV…
Shock-Cloud Interaction in the Solar Corona
Takahashi, Takuya
Flare-associated coronal shock waves sometimes interact with solar prominences, leading to large-amplitude prominence oscillations (LAPOs). Such prominence activation gives us a unique opportunity to track the time evolution of shock-cloud interaction in cosmic plasmas. Although the dynamics of interstellar shock-cloud interaction has been extensi…
The Discovery and Origin of a Very High-velocity Cloud Toward M33
Peek, J. E. G.; Zheng, Y.; Putman, M. E. +1 more
We report the detection of a largely ionized very high-velocity cloud (VHVC; vLSR∼ -350 km s-1) toward M33 with the Hubble Space Telescope/Cosmic Origin Spectrograph. The VHVC is detected in O I, C II, Si II, and Si III absorption along five sightlines separated by ∼ 0.06-0.4°. On sub-degree scales, the velocities and ionic c…
Spatial Offsets in Flare-CME Current Sheets
Giordano, Silvio; Raymond, John C.; Ciaravella, Angela
Magnetic reconnection plays an integral part in nearly all models of solar flares and coronal mass ejections (CMEs). The reconnection heats and accelerates the plasma, produces energetic electrons and ions, and changes the magnetic topology to form magnetic flux ropes and to allow CMEs to escape. Structures that appear between flare loops and CME …
First Characterization of the Neutral ISM in Two Local Volume Dwarf Galaxies
Cannon, John M.; Mizener, Andrew; Bralts-Kelly, Lilly +9 more
We present the first H I spectral-line images of the nearby, star-forming dwarf galaxies UGC 11411 and UGC 8245, acquired as part of the “Observing for University Classes” program with the Karl G. Jansky Very Large Array (VLA). These low-resolution images localize the H I gas and reveal the bulk kinematics of each system. Comparing with Hubble Spa…
First Detection of Sign-reversed Linear Polarization from the Forbidden [O I] 630.03 nm Line
de Wijn, A. G.; Socas-Navarro, H.; Vitas, N.
We report on the detection of linear polarization of the forbidden [O I] 630.03 nm spectral line. The observations were carried out in the broader context of the determination of the solar oxygen abundance, an important problem in astrophysics that still remains unresolved. We obtained spectro-polarimetric data of the forbidden [O I] line at 630.0…
Halo Pressure Profile through the Skew Cross-power Spectrum of the Sunyaev-Zel’dovich Effect and CMB Lensing in Planck
Cooray, Asantha; Feng, Chang; Keating, Brian +1 more
We measure the cosmic microwave background (CMB) skewness power spectrum in Planck, using frequency maps of the HFI instrument and the Sunyaev-Zel’dovich (SZ) component map. The two-to-one skewness power spectrum measures the cross-correlation between CMB lensing and the thermal SZ effect. We also directly measure the same cross-correlation using …
Radial Variations of Outward and Inward Alfvénic Fluctuations Based on Ulysses Observations
Wu, D. J.; Yang, L.; Shi, J. K. +4 more
Ulysses magnetic and plasma data are used to study hourly scale Alfvénic fluctuations in the solar polar wind. The calculated energy ratio {R}{vA}2(cal) of inward to outward Alfvén waves is obtained from the observed Walén slope through an analytical expression, and the observed {R}{vA}2<…
Accurate Orbital Solution for the New and Metal-poor Eclipsing Binary Tycho 5227-1023-1
Munari, U.; Zwitter, T.; Traven, G. +1 more
The orbit and physical parameters of the previously unsolved double-lined eclipsing binary Tyc 5227-1023-1, discovered during the search for RR Lyr variable candidate members of the Aquarius stream, are derived using high-resolution échelle spectroscopy and V,{I}\prime photometry. A synthetic spectral analysis of both components has be…