Search Publications
Insights into the Evolution of Five Isolated Galaxies
Wolter, A.; Uslenghi, M.; Marino, A. +3 more
Galaxy evolution is believed to be conditioned by the environment. Isolated galaxies or galaxies in poor groups are an excellent laboratory to study evolutionary mechanisms where effects of the environment are minimal. We present new Swift-UVOT data in six filters, three in the ultraviolet (UV), of five isolated galaxies aiming at shedding light i…
The CO Emission in the Taffy Galaxies (UGC 12914/15) at 60 pc Resolution. I. The Battle for Star Formation in the Turbulent Taffy Bridge
Boulanger, F.; Falgarone, E.; Braine, J. +8 more
We present Atacama Large Millimeter/submillimeter Array observations at a spatial resolution of 0.″2 (60 pc) of CO emission from the Taffy galaxies (UGC 12914/5). The observations are compared with narrowband Paα, mid-IR, radio continuum and X-ray imaging, plus optical spectroscopy. The galaxies have undergone a recent head-on collision, creating …
Ionized Carbon around IRC+10216
Smith, Nathan; Tram, Le Ngoc; Reach, William T. +5 more
Asymptotic giant branch stars create a rich inventory of molecules in their envelopes as they lose mass during later stages of their evolution. These molecules cannot survive the conditions in interstellar space, where they are exposed to ultraviolet photons of the interstellar radiation field. As a result, daughter molecules are the ones injected…
The Ultraviolet C II Lines as a Diagnostic of κ-distributed Electrons in Planetary Nebulae
Zhang, Yong; Yao, Zheng-Wei
Non-Maxwellian κ electron energy distributions (EEDs) have been proposed in recent years to resolve the so-called "electron temperature and abundance discrepancy problem" in the study of planetary nebulae (PNs). Thus the need to develop diagnostic tools to determine from observations the EED of PNs is raised. Arising from high-energy levels, the u…
H1821+643: The Most X-Ray and Infrared Luminous Active Galactic Nucleus (AGN) in the Swift/BAT Survey in the Process of Rapid Stellar and Supermassive Black Hole Mass Assembly
Hashimoto, Takuya; Ricci, Claudio; Izumi, Takuma +6 more
H1821+643 is the most X-ray luminous nonbeamed active galactic nucleus (AGN) of L 14-150 keV = 5.2 × 1045 erg s-1 in the Swift/Burst Alert Telescope (BAT) ultrahard X-ray survey, and it is also a hyperluminous infrared (IR) galaxy L IR = 1013.2 L ⊙ residing in the center of a massiv…
Recent Formation of a Spiral Disk Hosting Progenitor Globular Clusters at the Center of the Perseus Brightest Cluster Galaxy. II. Progenitor Globular Clusters
Ohyama, Youichi; Lim, Jeremy; Wong, Emily +1 more
We address the nature and origin of super star clusters (SSCs) discovered by Holtzman et al. within a radius of ~5 kpc from the center of NGC 1275, the giant elliptical galaxy at the center of the Perseus Cluster. We show that, in contrast with the much more numerous population of SSCs subsequently discovered up to ~30 kpc from the center of this …
Long-term Evolution of Postexplosion Helium-star Companions of Type Iax Supernovae
Han, Zhanwen; McCully, Curtis; Heger, Alexander +3 more
Supernovae of Type Iax (SNe Iax) are an accepted faint subclass of hydrogen-free supernovae. Their origin, the nature of the progenitor systems, however, is an open question. Recent studies suggest that the weak deflagration explosion of a near-Chandrasekhar-mass white dwarf in a binary system with a helium-star donor could be the origin of SNe Ia…
Multispacecraft Remote Sensing and In Situ Observations of the 2020 November 29 Coronal Mass Ejection and Associated Shock: From Solar Source to Heliospheric Impacts
Liu, Ying D.; Zhu, Bei; Chen, Chong
We investigate the source eruption, propagation and expansion characteristics, and heliospheric impacts of the 2020 November 29 coronal mass ejection (CME) and associated shock, using remote sensing and in situ observations from multiple spacecraft. A potential-field source-surface model is employed to examine the coronal magnetic fields surroundi…
Magnetic Imprints of Eruptive and Noneruptive Solar Flares as Observed by Solar Dynamics Observatory
Ravindra, B.; Doddamani, V. H.; Vemareddy, P. +1 more
The abrupt and permanent changes of the photospheric magnetic field in the localized regions of active regions during solar flares, called magnetic imprints (MIs), have been observed for nearly the past three decades. The well-known coronal implosion model is assumed to explain such flare-associated changes but the complete physical understanding …
Toward Understanding the B[e] Phenomenon. IX. Nature and Binarity of MWC645
Miroshnichenko, A. S.; Manset, N.; Zharikov, S. V. +14 more
We present the results of optical and near-IR spectroscopy and multicolor photometry of the emission-line star MWC 645, which exhibits the B[e] phenomenon. The presence of positionally variable absorption lines of a cool star detected for the first time indicates that the object is a binary system. Using a combination of the photometric and spectr…