Search Publications
Discovery of an Outbursting 12.8 Minute Ultracompact X-Ray Binary
Udalski, Andrzej; Mróz, Przemek; Skowron, Jan +2 more
We report the discovery of OGLE-UCXB-01, a 12.8 minute variable object located in the central field of Galactic bulge globular cluster Djorg 2. The presence of frequent, short-duration brightenings at such an ultrashort period in long-term OGLE photometry together with the blue color of the object in Hubble Space Telescope images and the detection…
Determination of Plasma, Pickup Ion, and Suprathermal Particle Spectrum in the Solar Wind Frame of Reference
Wimmer-Schweingruber, R. F.; Pogorelov, N. V.; von Steiger, R. +4 more
Particle spectra directly measured by a plasma or low-energy particle experiment on spacecraft often contain instrumental effects due to a limited field of view or angular resolution. It is because the particle distribution function at low energies is highly anisotropic in the spacecraft frame of reference, in which the measurements are made. In t…
Multiwavelength Stereoscopic Observation of the 2013 May 1 Solar Flare and CME
Krucker, Säm; Masuda, Satoshi; Mitrofanov, Igor +7 more
A M-class behind-the-limb solar flare on 2013 May 1 (SOL2013-05-01T02:32), accompanied by a (∼400 km s-1) coronal mass ejection (CME), was observed by several space-based observatories with different viewing angles. We investigated the RHESSI-observed occulted hard X-ray (HXR) emissions that originated at least 0.1 {R}{{S}} a…
Evolution of the Three-dimensional Shape of Passively Evolving and Star-forming Galaxies at z < 1
Kajisawa, Masaru; Satoh, Yuki K.; Himoto, Kazuharu G.
Using the HST/ACS I F814W-band data, we investigated the distribution of apparent axial ratios of ∼21,000 galaxies with M V < -20 at 0.2 < z < 1.0 in the COSMOS field as a function of stellar mass, specific star formation rate (sSFR), and redshift. We statistically estimated intrinsic 3D shapes of these galaxies by…
Chromospheric Peculiar Off-limb Dynamical Events from IRIS Observations
Koutchmy, S.; Tavabi, E.
To study motions and oscillations in the solar chromosphere and at the transition region level we analyze some extreme Doppler shifts observed off-limb with the Interface Region Imaging Spectrograph (IRIS). Raster scans and slit-jaw imaging observations performed in the near-ultraviolet channels were used. Large transverse oscillations are reveale…
Limits on the Electromagnetic Counterpart of Binary Black Hole Coalescence at Visible Wavelengths
Turpin, Damien; Laugier, Romain; Noysena, Kanthanakorn +4 more
We used the Télescope à Action Rapide pour les Objets Transitoires network of telescopes to search for the electromagnetic counterparts of GW150914, GW170104, and GW170814, which were reported to originate from binary black hole merger events by the Laser Interferometer Gravitational-wave Observatory and Virgo collaborations. Our goal is to constr…
The K2 Light Curves and Stunted Outbursts of AC Cnc
Schlegel, E. M.; Honeycutt, R. K.
We describe two observations of the nova-like cataclysmic variable AC Cnc obtained with Kepler during its revamped second mission (K2). Using the K2 1 minute cadence mode, the data were obtained during campaigns 5 and 18. Campaign 5 (C05) lasted from ∼2015 April 27 to ∼2015 July 10, a total of 74.8 days, and yielded ∼106,000 measurements. Campaign…
The Broadband X-Ray Spectrum of the X-Ray-obscured Type 1 AGN 2MASX J193013.80+341049.5
Walton, Dominic J.; Stern, Daniel; Assef, Roberto J. +6 more
We present results from modeling the broadband X-ray spectrum of the Type 1 active galactic nucleus (AGN) 2MASX J193013.80+341049.5 using NuSTAR, Swift, and archival XMM-Newton observations. We find this source to be highly X-ray obscured, with column densities exceeding 1023 cm-2 across all epochs of X-ray observations, span…
Triangulum-Andromeda Overdensity: a Region with a Complex Stellar Population
Souto, Diogo; Cunha, K.; Majewski, S. R. +4 more
The Triangulum-Andromeda (TriAnd) overdensity is a distant structure of the Milky Way located in the second Galactic quadrant well below the Galactic plane. Since its discovery, its nature has been under discussion, whether it could be old perturbations of the Galactic disk or the remains of a disrupted former dwarf galaxy. In this study, we inves…
Magnetic Stability of Massive Star-forming Clumps in RCW 106
Kusune, Takayoshi; Nakamura, Fumitaka; Tamura, Motohide +6 more
The RCW 106 molecular cloud complex is an active massive star-forming region where a ministarburst is taking place. We examined its magnetic structure by near-IR polarimetric observations with the imaging polarimeter SIRPOL on the IRSF 1.4 m telescope. The global magnetic field is nearly parallel to the direction of the Galactic plane and the clou…