15 research outputs found
GeV Analysis of Mixed Morphology Supernova Remnants Interacting with Molecular Clouds
The first remnants detected by the Fermi Gamma-ray Space Telescope were of
the type of mixed-morphology supernova remnants interacting with molecular
clouds. In this paper we are presenting preliminary results of the gamma-ray
analysis of 4 selected mixed morphology remnants, G359.1-0.5, G337.8-0.1,
G001.0-0.1, and G346.6-0.2, as well as G349.7+0.2, in the 0.2 - 300 GeV energy
range from the data collected by Fermi Gamma-ray Space Telescope for 3 years.
G359.1-0.5, G337.8-0.1, and G349.7+0.2 were all detected with significances
above 5 sigma. The excess distribution of G359.1-0.5 shows extended gamma-ray
emission, which coincides with the TeV gamma-ray source HESS J1745-303.
G337.8-0.1 also shows an extended nature.Comment: High Energy Gamma-Ray Astronomy: 5th International Meeting on High
Energy Gamma-Ray Astronom
Searching for Overionized Plasma in the Gamma-ray Emitting Supernova Remnant G349.70.2
G349.70.2 is a supernova remnant (SNR) expanding in a dense medium of
molecular clouds and interacting with clumps of molecular material emitting
gamma rays. We analyzed the gamma-ray data of Large Area Telescope on board
Fermi Gamma Ray Space Telescope and detected G349.70.2 in the energy range
of 0.2300 GeV with a significance of 13 showing no extended
morphology. Modeling of the gamma-ray spectrum revealed that the GeV gamma-ray
emission dominantly originates from the decay of neutral pions, where the
protons follow a broken power-law distribution with a spectral break at
12 GeV. To search for features of radiative recombination continua in the
eastern and western regions of the remnant, we analyzed the Suzaku data of
G349.70.2 and found no evidence for overionized plasma. In this paper we
discuss possible scenarios to explain the hadronic gamma-ray emission in
G349.70.2 and the mixed morphology nature of this SNR.Comment: 10 pages, 7 figures; accepted by ApJ. arXiv admin note: text overlap
with arXiv:1406.217
Recombining Plasma in the Gamma-ray Emitting Mixed-Morphology Supernova Remnant 3C 391
A group of middle-aged mixed-morphology (MM) supernova remnants (SNRs)
interacting with molecular clouds (MC) has been discovered as strong GeV
gamma-ray emitters by Large Area Telescope on board Fermi Gamma Ray Space
Telescope (Fermi-LAT). The recent observations of the Suzaku X-ray satellite
have revealed that some of these interacting gamma-ray emitting SNRs, such as
IC443, W49B, W44, and G359.1-0.5, have overionized plasmas. 3C 391 (G31.9+0.0)
is another Galactic MM SNR interacting with MC. It was observed in GeV gamma
rays by Fermi-LAT as well as in the 0.3 10.0 keV X-ray band by Suzaku. In
this work, 3C 391 was detected in GeV gamma rays with a significance of
18 and we showed that the GeV emission is point-like in nature. The
GeV gamma-ray spectrum was shown to be best explained by the decay of neutral
pions assuming that the protons follow a broken power-law distribution. We
revealed radiative recombination structures of silicon and sulfur from 3C 391
using Suzaku data. In this paper we discuss the possible origin of this type of
radiative plasma and hadronic gamma rays.Comment: 10 pages, 7 figures; accepted by Ap
A possible optical counterpart of the X-ray source NuSTARJ053449+2126.0
In this work, we report the observation of a possible optical counterpart to
the recently discovered X-ray source NuSTAR J053449+2126.0. To search for an
optical counterpart of NuSTAR J053449+2126.0 (J0534 in short), we observed the
source with the 1.5-m Telescope (RTT150). Using the B, V, R, and I images of
J0534, we detected the possible optical counterpart of J0534 and determined,
based on our spectral analysis, the source distance for the first time. J0534
could be a high-redshift member of an Active Galactic Nucleus (AGN) sub-group
identified as a quasar. Our analysis favours an accreting black hole of mass
as a power supply for the quasar in J0534.
Further observations in optical and other wavelengths are needed to confirm its
nature.Comment: 7 pages, 4 figure
Planetary migration in evolving planetesimals discs
In the current paper, we further improved the model for the migration of
planets introduced in Del Popolo et al. (2001) and extended to time-dependent
planetesimal accretion disks in Del Popolo and Eksi (2002). In the current
study, the assumption of Del Popolo and Eksi (2002), that the surface density
in planetesimals is proportional to that of gas, is released. In order to
obtain the evolution of planetesimal density, we use a method developed in
Stepinski and Valageas (1997) which is able to simultaneously follow the
evolution of gas and solid particles for up to 10^7 yrs. Then, the disk model
is coupled to migration model introduced in Del Popolo et al. (2001) in order
to obtain the migration rate of the planet in the planetesimal. We find that
the properties of solids known to exist in protoplanetary systems, together
with reasonable density profiles for the disk, lead to a characteristic radius
in the range 0.03-0.2 AU for the final semi-major axis of the giant planet.Comment: IJMP A in prin
Uniform Contribution of Supernova Explosions to the Chemical Enrichment of Abell 3112 out to R 200
The spatial distribution of the metals residing in the intra-cluster medium (ICM) of galaxy clusters records all the information on a cluster's nucleosynthesis and chemical enrichment history. We present measurements from a total of 1.2 Ms Suzaku XIS and 72 ks Chandra observations of the cool-core galaxy cluster Abell 3112 out to its virial radius (~1470 kpc). We find that the ratio of the observed supernova type Ia explosions to the total supernova explosions has a uniform distribution at a level of 12%–16% out to the cluster's virial radius. The observed fraction of type Ia supernova explosions is in agreement with the corresponding fraction found in our Galaxy and the chemical enrichment of our Galaxy. The non-varying supernova enrichment suggests that the ICM in cluster outskirts was enriched by metals at an early stage before the cluster itself was formed during a period of intense star formation activity. Additionally, we find that the 2D delayed detonation model CDDT produce significantly worse fits to the X-ray spectra compared to simple 1D W7 models. This is due to the relative overestimate of Si, and the underestimate of Mg in these models with respect to the measured abundances.United States. National Aeronautics and Space Administration (NNX09AV65G)United States. National Aeronautics and Space Administration (NNX10AV02G
Suzaku Analysis of Galactic Supernova Remnants G27.4+0.0 and G12.0-0.1
We present Suzaku results of galactic supernova remnants (SNRs) G27.4 +0.0 and G12.0-0.1. From the spectra some important parameters like galactic hydrogen column density (N-H), electron temperature (kT(e)), ionization timescale (n(e)t) are calculated. Furthermore, the abundances of Mg, Si, S are derived from the spectra of G27.4+0.0 indicating that G27.4+0.0 has originated from a core-collapse supernova explosion
TURKISH NATIONAL OBSERVATORY (TUG) VIEW OF CLUSTERS OF GALAXIES
We present the results of the optical observations of clusters of galaxies trough photometric observations with RTT150 telescope. We have selected a sample of 10 nearby (z < 1.2) Abell clusters from the northern sky. Properties of the extended X-ray intra-cluster medium (ICM) are studied using Chandra and XMM-Newton archival data. Considering possible relations of X-ray and radio plasma, the extended radio halo and jets are studied. The intent of our observations is to map galaxy densities in the optical band and to define sub-clustering if there is any. The X-ray (temperature and metal distributions) and radio features, combined with galaxy distributions are used to diagnose morphology, structure and evolutional history of the clusters