Search Publications
Constraining Stellar Parameters and Atmospheric Dynamics of the Carbon AGB star V Oph
Ohnaka, Keiichi; Carpenter, Kenneth G.; Rau, Gioia +2 more
Molecules and dust produced by the atmospheres of cool evolved stars contribute to a significant amount of the total material found in the interstellar medium. To understand the mechanism behind the mass loss of these stars, it is of pivotal importance to investigate the structure and dynamics of their atmospheres. Our goal is to verify if the ext…
The Weakening Outburst of the Young Eruptive Star V582 Aur
Cseh, B.; Kriskovics, L.; Pál, A. +17 more
V582 Aur is a pre-main-sequence FU Orionis type eruptive star, which entered a brightness minimum in 2016 March due to changes in the line-of-sight extinction. Here, we present and analyze new optical B, V, R C , and I C band multiepoch observations and new near-infrared J, H, and K S band photometric measurem…
A Statistical Study of the Magnetic Imprints of X-class Solar Flares
Ding, Mingde; Guo, Yang; Zhang, Yining +3 more
Magnetic imprints, the rapid and irreversible evolution of photospheric magnetic fields as feedback from flares in the corona, have been confirmed by many previous studies. These studies showed that the horizontal field will permanently increase at the polarity inversion line (PIL) after eruptions, indicating that a more horizontal geometry of the…
ALMA Observations of the Molecular Gas in the Elliptical Galaxy NGC 3557
Espada, Daniel; Cepa, Jordi; Vila-Vilaro, Baltasar +3 more
We present the results of CO interferometric observations of the southern elliptical galaxy NGC 3557 with ALMA. We have detected both the CO(1-0) emission line and a relatively strong continuum at 3 mm. The continuum shows a flat-spectrum central unresolved source (at our angular resolution of 0.″7) and two jets, associated with the larger-scale e…
Asymptotic Giant Branch Stars in the Nearby Dwarf Galaxy Leo P
van Loon, J. Th.; Zijlstra, A. A.; Skillman, E. D. +7 more
We have conducted a highly sensitive census of the evolved-star population in the metal-poor dwarf galaxy Leo P and detected four asymptotic giant branch (AGB) star candidates. Leo P is one of the best examples of a nearby analog of high-redshift galaxies because of its primitive metal content (2% of the solar value), proximity, and isolated natur…
High-velocity Bullets from V Hydrae, an Asymptotic Giant Branch Star in Transition: Ejection History and Spatio-kinematic Modeling
Sahai, R.; Morris, M. R.; Scibelli, S.
The carbon star V Hydrae (V Hya) provides new insight into the nature of the launching mechanism of jet-like outflows that are believed to be the cause of the poorly understood transition phase of asymptotic giant branch stars into aspherical planetary nebulae. V Hya has been shown to periodically eject collimated gas blobs at high velocities (“bu…
Investigating Early-type Galaxy Evolution with a Multiwavelength Approach. III. Insights from SPH Simulations with Chemophotometric Implementation
Mazzei, Paola; Rampazzo, Roberto; Marino, Antonietta +3 more
We are exploring galaxy evolution in low-density environments exploiting smooth particle hydrodynamic simulations, including chemophotometric implementation. From a large grid of simulations of galaxy encounters and mergers starting from triaxial halos of gas and dark matter, we single out the simulations matching the global properties of our targ…
A Search for Analogs of KIC 8462852 (Boyajian’s Star): A Proof of Concept and the First Candidates
Schmidt, Edward G.
The seemingly normal F dwarf, KIC 8462852 (a.k.a. Boyajian’s Star), has been observed to exhibit two types of behavior unique among known variable stars: infrequent episodes of small brightness dips and a long-term decline in brightness between the dips. No satisfactory mechanism has been found for this behavior, at least in part, because there is…
Star Clusters in the Elliptical Galaxy NGC 4589 Hosting a Calcium-rich SN Ib (SN 2005cz)
Lee, Myung Gyoon; Kang, Jisu; Jang, In Sung
NGC 4589, a bright E2 merger-remnant galaxy, hosts the peculiar fast and faint calcium-rich SN Ib SN 2005cz. The progenitor of Ca-rich SNe Ib has been controversial: it could be (1) a young, massive star with 6-12 M ⊙ in a binary system, or (2) an old, low-mass star in a binary system that was kicked out from the galaxy center. Moreover…
A Mini Survey of Methyl Cyanide toward Extended Green Objects
Liu, Sheng-Yuan; Chen, Huei-Ru; Su, Yu-Nung +4 more
We present results of a survey of methyl cyanide (CH3CN) J = 12-11 toward 56 sources, including 35 Extended Green Objects (EGOs) and 21 nearby AKARI counterparts, with the Submillimeter Telescope (SMT) in order to characterize the nature of EGOs. CH3CN, a tracer of hot core emission, is detected in 19 EGOs (∼54%) and five AKA…