Search Publications
Detection of a Star-forming Galaxy in the Center of a Low-mass Galaxy Cluster
Lovisari, Lorenzo; Andrade-Santos, Felipe; Jones, Christine +4 more
Brightest Cluster Galaxies (BCGs) residing in the centers of galaxy clusters are typically quenched giant ellipticals. A recent study hinted that star-forming galaxies with large disks, so-called superluminous spirals and lenticulars, are the BCGs of a subset of galaxy clusters. Based on the existing optical data it was not possible to constrain w…
Toward a Measurement of the Transverse Peculiar Velocity of Galaxy Pairs
Darling, Jeremy; Truebenbach, Alexandra E.
The transverse peculiar velocities caused by the mass distribution of large-scale structure (LSS) provide a test of the theoretical matter power spectrum and the cosmological parameters that contribute to its shape. Typically, the matter density distribution of the nearby universe is measured through redshift or line-of-sight peculiar velocity sur…
Revisiting the Iron Abundance in the Hyper Iron-poor Star HE 1327-2326 with UV COS/HST Data
Ezzeddine, Rana; Frebel, Anna
We present a new iron abundance analysis of the hyper metal-poor star HE 1327-2326, based on Fe II lines detected in its UV spectral range for the first time. In a Cosmic Origins Spectrograph (COS) spectrum, five new Fe II lines could be measured. A Si I line was also detected for the first time. We determine a 1D local thermodynamic equilibrium (…
Chandra Observations of NuSTAR Serendipitous Sources near the Galactic Plane
Aird, James; Stern, Daniel; Rahoui, Farid +8 more
The Nuclear Spectroscopic Telescope Array (NuSTAR) serendipitous survey has already uncovered a large number of active galactic nuclei (AGNs), providing new information about the composition of the cosmic X-ray background. For AGNs off the Galactic plane, it has been possible to use existing X-ray archival data to improve source localizations, ide…
Association between Tornadoes and Instability of Hosting Prominences
Poedts, Stefaan; Shergelashvili, Bidzina M.; Mghebrishvili, Irakli +4 more
We studied the dynamics of all prominence tornadoes detected by the Solar Dynamics Observatory/Atmospheric Imaging Assembly from 2011 January 01 to December 31. In total, 361 events were identified during the whole year, but only 166 tornadoes were traced until the end of their lifetime. Out of 166 tornadoes, 80 (48%) triggered CMEs in hosting pro…
3D Electric Waveforms of Solar Wind Turbulence
Goetz, K.; Kellogg, P. J.; Monson, S. J.
Electric fields provide the major coupling between the turbulence of the solar wind and particles. A large part of the turbulent spectrum of fluctuations in the solar wind is thought to be kinetic Alfvén waves; however, whistlers have recently been found to be important. In this article, we attempt to determine the mode identification of individua…
Exploring the Spectral Variability of the Ultraluminous X-Ray Source M81 X-6 with Suzaku and XMM-Newton
Jithesh, V.; Misra, Ranjeev
We present X-ray spectral variability studies of the ultraluminous X-ray source (ULX) M81 X-6 using Suzaku and XMM-Newton observations performed during 2001-2015. The spectra were first fitted by a standard multitemperature disk and a thermal Comptonization component that revealed spectral variability where the primary distinction is the change in…
The First Glitch in a Central Compact Object Pulsar: 1E 1207.4-5209
Gotthelf, E. V.; Halpern, J. P.
Since its discovery as a pulsar in 2000, the central compact object (CCO) 1E 1207.4-5209 in the supernova remnant PKS 1209-51/52 had been a stable 0.424 s rotator with an extremely small spin-down rate and weak ({B}s≈ 9× {10}10 G) surface dipole magnetic field. In 2016 we observed a glitch from 1E 1207.4-5209 of at least {{Δ …
Searching Ultra-compact Pulsar Binaries with Abnormal Timing Behavior
Gong, B. P.; Li, Y. P.; Yuan, J. P. +8 more
Ultra-compact pulsar binaries are both ideal sources of gravitational radiation for gravitational wave detectors and laboratories for fundamental physics. However, the shortest orbital period of all radio pulsar binaries is currently 1.6 hr. The absence of pulsar binaries with a shorter orbital period is most likely due to technique limit. This pa…
Formation of Large-scale Coronal Loops Interconnecting Two Active Regions through Gradual Magnetic Reconnection and an Associated Heating Process
Liu, Chang; Wang, Haimin; Chen, Yao +5 more
Coronal loops interconnecting two active regions (ARs), called interconnecting loops (ILs), are prominent large-scale structures in the solar atmosphere. They carry a significant amount of magnetic flux and therefore are considered to be an important element of the solar dynamo process. Earlier observations showed that eruptions of ILs are an impo…