Search Publications
Interstellar dust distribution outside the heliopause: deflection at the heliospheric interface
Katushkina, O. A.; Izmodenov, V. V.; Alexashov, D. B. +1 more
We developed a numerical model of the interstellar dust distribution in the global heliosphere including the heliospheric interface, where the solar wind plasma interacts with the local interstellar plasma. The model is based on the plasma distributions obtained by the 3D kinetic-magnetohydrodynamic model of the heliospheric interface developed by…
Globular Clusters and Spur Clusters in NGC 4921, the Brightest Spiral Galaxy in the Coma Cluster
Lee, Myung Gyoon; Jang, In Sung
We resolve a significant fraction of globular clusters (GCs) in NGC 4921, the brightest spiral galaxy in the Coma cluster. We also find a number of extended bright star clusters (star complexes) in the spur region of the arms. The latter are much brighter and bluer than those in the normal star-forming region, being as massive as 3 × 105
On the running of the spectral index to all orders: a new model-dependent approach to constrain inflationary models
Zarei, Moslem
In conventional model-independent approaches, the power spectrum of primordial perturbations is characterized by such free parameters as the spectral index, its running, the running of running, and the tensor-to-scalar ratio. In this work we show that, at least for simple inflationary potentials, one can find the primordial scalar and tensor power…
Discovery of the Candidate Off-nuclear Ultrasoft Hyper-luminous X-Ray Source 3XMM J141711.1+522541
Romanowsky, Aaron J.; Ramirez-Ruiz, Enrico; Strader, Jay +8 more
We report the discovery of an off-nuclear ultrasoft hyper-luminous X-ray source candidate 3XMM J141711.1+522541 in the inactive S0 galaxy SDSS J141711.07+522540.8 (z = 0.41827, dL = 2.3 Gpc) in the Extended Groth Strip. It is located at a projected offset of ∼1.″0 (5.2 kpc) from the nucleus of the galaxy and was serendipitously detected…
X-ray observations of dust obscured galaxies in the Chandra deep field south
Salvato, M.; Vignali, C.; Ranalli, P. +6 more
We present the properties of X-ray detected dust obscured galaxies (DOGs) in the Chandra deep field south. In recent years, it has been proposed that a significant percentage of the elusive Compton-thick (CT) active galactic nuclei (AGN) could be hidden among DOGs. This type of galaxy is characterized by a very high infrared (IR) to optical flux r…
Two Exceptions in the Large SEP Events of Solar Cycles 23 and 24
Gopalswamy, N.; Yashiro, S.; Mäkelä, P. +3 more
We discuss our findings from a survey of all large solar energetic particle (SEP) events of Solar Cycles 23 and 24, i.e. the SEP events where the intensity of > 10 MeV protons observed by GOES was > 10 pfu. In our previous work (Gopalswamy et al. in Geophys. Res. Lett. 41, 2673, 2014) we suggested that ground level enhancements (GLEs) in Cyc…
Earliest phases of star formation (EPoS). Dust temperature distributions in isolated starless cores
Henning, Th.; Krause, O.; Balog, Z. +10 more
Context. Stars form by the gravitational collapse of cold and dense molecular cloud cores. Constraining the temperature and density structure of such cores is fundamental for understanding the initial conditions of star formation. We use Herschel observations of the thermal far-infrared (FIR) dust emission from nearby and isolated molecular cloud …
Herschel/PACS far-IR spectral imaging of a jet from an intermediate mass protostar in the OMC-2 region
Manoj, P.; Megeath, S. T.; Watson, D. M. +10 more
We present the first detection of a jet in the far-IR [O I] lines from an intermediate mass protostar. This jet was detected in a Herschel/PACS spectral mapping study in the [O I] lines of OMC-2 FIR 3 and FIR 4, two of the most luminous protostars in Orion outside of the Orion Nebula. The spatial morphology of the fine structure line emission reve…
Hubble Space Telescope Proper Motions of Individual Stars in Stellar Streams: Orphan, Sagittarius, Lethe, and the New "Parallel’ Stream"
Anderson, Jay; Law, David R.; van der Marel, Roeland P. +6 more
We present a multi-epoch Hubble Space Telescope (HST) study of stellar proper motions (PMs) for four fields along the Orphan Stream. We determine absolute PMs of several individual stars per target field using established techniques that utilize distant background galaxies to define a stationary reference frame. Five Orphan Stream stars are identi…
The curious temporal behavior of the frequency of different class flares
Zhong, J.; Gao, P. X.
We investigate the frequency of all (X-ray flare events higher than class B1.0), B, C, M and X-class flares, respectively, derived from the National Geophysical Data Center (NGDC) list of solar flares between May 1983 and September 2014, which corresponds to the two complete solar cycles (SCs) 22 and 23 as well as the rise and maximum phases of SC…