Search Publications
Eruption of the EUV Hot Channel from the Solar Limb and Associated Moving Type IV Radio Burst
Zhang, J.; Démoulin, P.; Gopalswamy, N. +3 more
Using the observations from the Solar Dynamics Observatory, we study an eruption of a hot-channel flux rope (FR) near the solar limb on 2015 February 9. The pre-eruptive structure is visible mainly in EUV 131 Å images, with two highly sheared loop structures. They undergo a slow rising motion and then reconnect to form an eruptive hot channel, as …
Vibrationally Excited Lines of HC3N Associated with the Molecular Disk around the G24.78+0.08 A1 Hypercompact H II Region
Nakamura, Fumitaka; Takakuwa, Shigehisa; Taniguchi, Kotomi +7 more
We have analyzed Atacama Large Millimeter/submillimeter Array Band 6 data of the hypercompact H II region G24.78+0.08 A1 (G24 HC H II) and report the detection of vibrationally excited lines of HC3N (v 7 = 2, J = 24 - 23). The spatial distribution and kinematics of a vibrationally excited line of HC3N (v 7
Dense Gas and Star Formation in Nearby Infrared-bright Galaxies: APEX Survey of HCN and HCO+ J = 2 → 1
Wang, Junzhi; Gao, Yu; Zhang, Zhi-Yu +6 more
Both Galactic and extragalactic studies of star formation suggest that stars form directly from dense molecular gas. To trace such high volume density gas, HCN and HCO+ J = 1 → 0 have been widely used for their high dipole moments, relatively high abundances, and often being the strongest lines after CO. However, HCN and HCO+…
Surveying the Giant H II Regions of the Milky Way with SOFIA. IV. Sgr D, W42, and a Reassessment of the Giant H II Region Census
Lim, Wanggi; Karnath, Nicole; De Buizer, James M. +2 more
This is the fourth paper exploring the infrared properties of giant H II regions with the FORCAST instrument on the Stratospheric Observatory For Infrared Astronomy (SOFIA). Our survey utilizes the census of 56 Milky Way giant H II regions identified by Conti & Crowther, and in this paper we present the 20 and 37 µm imaging data we obtai…
Eta Carinae: An Evolving View of the Central Binary, Its Interacting Winds and Its Foreground Ejecta
Hamaguchi, Kenji; Corcoran, Michael F.; Russell, Christopher M. P. +13 more
FUV spectra of η Car, recorded across two decades with HST/STIS, document multiple changes in resonant lines caused by dissipating extinction in our line of sight. The FUV flux has increased nearly tenfold, which has led to increased ionization of the multiple shells within the Homunculus and photodestruction of H2. Comparison of observ…
Effect of the Heliospheric State on CME Evolution
Gopalswamy, Nat; Akiyama, Sachiko; Yashiro, Seiji +2 more
The culmination of solar cycle 24 by the end of 2019 has created the opportunity to compare the differing properties of coronal mass ejections (CMEs) between two whole solar cycles: solar cycle 23 (SC 23) and solar cycle 24 (SC 24). We report on the width evolution of limb CMEs in SCs 23 and 24 in order to test the suggestion by Gopalswamy et al. …
Y Gem: A White Dwarf Symbiotic Star?
Wang, Q. Daniel; Shao, Yong; Li, Xiang-Dong +2 more
In this work we conduct a thorough investigation of the X-ray and ultraviolet (UV) properties of Y Gem based on six archival XMM-Newton and Chandra observations to explore the nature of the system. The results show that Y Gem has strong (1032-34 erg s-1) X-ray emission, including a hard (with a maximum emission temperature of…
First Images of the Molecular Gas around a Born-again Star Revealed by ALMA
Treviño-Morales, Sandra P.; Toalá, Jesús A.; Guerrero, Martín A. +7 more
Born-again stars allow probing stellar evolution in human timescales and provide the most promising path for the formation of hydrogen-deficient post-asymptotic giant branch objects, but their cold and molecular components remain poorly explored. Here we present ALMA observations of V 605 Aql that unveil for the first time the spatio-kinematic dis…
Gas and Dust Shadows in the TW Hydrae Disk
Andrews, Sean M.; Bae, Jaehan; Huang, Jane +4 more
We present new observations of CO J = 2 - 1 emission from the protoplanetary disk around TW Hya. Emission is detected out to 240 au (4″) and found to exhibit azimuthal variations up to 20% beyond 180 au (3″), with the west side of the disk brighter than the east. This asymmetry is interpreted as tracing the shadow previously seen in scattered ligh…
The Quantitative Relation of the Time Profiles of Intensities in the Well-connected Solar Energetic Particle Events
Wang, Yang; Lyu, Dan; Qin, Gang +1 more
In this work, the quantitative relation of the intensity time profiles in the well-connected energetic particle events has been identified. Focusing on the propagation processes of energetic protons in the energy channels of about 13-64 MeV, solar energetic particle (SEP) events observed by STEREO A, STEREO B, and SOHO have been studied. The inten…