2,165 research outputs found
Statistical Re-examination of Reported Emission Lines in the X-ray Afterglow of GRB 011211
(abridged) A 0.2-12 keV spectrum obtained with the XMM EPIC/pn instrument of
GRB 011211 was found by Reeves et al. (2002) to contain emission lines which
were interpreted to be from Mg XI, Si XIV, S XVI, Ar XVIII, and Ca XX, at a
lower redshift (z_{obs}=1.88) than the host galaxy (z_{host}=2.14). We examine
the spectrum independently, and find that the claimed lines would not be
discovered in a blind search. Specifically, Monte Carlo simulations show that
they would be observed in 10% of featureless spectra with the same
signal-to-noise. Imposing a model in which the two brightest lines would be Si
XIV and S XVI K-alpha emission possibly velocity shifted to between
z=1.88--2.40, such features would be found in between ~1.2-2.6% of observed
featureless spectra. We find the detection significances to be insufficient to
justify the claim of detection and the model put forth to explain them. K-alpha
line complexes are also found at z=1.2 and z=2.75 of significance equal to or
greater than that at z=1.88. If one adopts the z=1.88 complex as significant,
one must also adopt the other two complexes to be significant. The
interpretation of these data in the context of the model proposed by Reeves et
al. is therefore degenerate, and cannot be resolved by these data alone.Comment: 23 pages, 4 figures. MNRAS, accepted. Expanded discussio
The Soft X-ray Spectrum from NGC 1068 Observed with LETGS on Chandra
Using the combined spectral and spatial resolving power of the Low Energy
Transmission Grating (LETGS) on board Chandra, we obtain separate spectra from
the bright central source of NGC 1068 (Primary region), and from a fainter
bright spot 4" to the NE (Secondary region). Both spectra are dominated by line
emission from H- and He-like ions of C through S, and from Fe L-shell ions, but
also include narrow radiative recombination continua, indicating that most of
the soft X-ray emission arises in low-temperature (kT few eV) photoionized
plasma. We confirm the conclusions of Kinkhabwala et al. (2002), based on
XMM-Newton RGS observations, that the entire nuclear spectrum can be explained
by recombination/radiative cascade following photoionization, and radiative
decay following photoexcitation, with no evidence for hot, collisionally
ionized plasma. In addition, this model also provides an excellent fit to the
spectrum of the Secondary region, albeit with radial column densities a factor
of three lower, as would be expected given its distance from the source of the
ionizing continuum. The remarkable overlap and kinematical agreement of the
optical and X-ray line emission, coupled with the need for a distribution of
ionization parameter to explain the X-ray spectra, collectively imply the
presence of a distribution of densities (over a few orders of magnitude) at
each radius in the ionization cone. Relative abundances of all elements are
consistent with Solar abundance, except for N, which is 2-3 times Solar. The
long wavelength spectrum beyond 30 A is rich of L-shell transitions of Mg, Si,
S, and Ar, and M-shell transitions of Fe. The velocity dispersion decreases
with increasing ionization parameter, as deduced from these long wavelength
lines and the Fe-L shell lines.Comment: 12 pages, 11 figures, accepted for publication in Astronomy and
Astrophysic
Analisis Pendapatan Usaha Industri Jamu di Kelompok Tani Prima Mandiri Desa Usapinonot
Penelitian ini dilakukan di Kecamatan Insana Barat Kabupaten Timor Tengah Utara, tujuan penelitian ini untuk mengetahui pendapatan USAha industri jamu di Kelompok Tani Prima Mandiri, dan untuk mengetahui keuntungan relatif USAha industri jamu di Kelompok Tani Mandiri. Metode pengambilan data dilakukan secara survei dengan jenis data berupa data primer dan data sekunder. Analisis data dilakukan dengan menggunakan analisis deskriptif, analisis pendapatan dan analisis R/C ratio. Hasil penelitian ini menunjukkan beberapa kesimpulan yakni, penerimaan untuk keseluruhan responden dalam empat kali produksi (1 bulan) adalah sebesar Rp. 44.000.000 dengan rata-rata per responden adalah sebesar Rp. 4.000.000. Total biaya produksi untuk keseluruhan responden dalam empat kali produksi (bulan) adalah sebesar Rp. 18.329.500 dengan rata-rata Rp. 1.666.318 per responden. Total pendapatan USAha industri jamu untuk keseluruhan responden dalam satu kali produksi adalah sebesar Rp. 4.776.500 dengan rata-rata Rp. 434.277, sedangkan total pendapatan untuk keseluruhan responden dalam empat kali produksi (bulan) adalah sebesar Rp. 19.248.000 dengan rata-rata per responden adalah sebesar Rp.1.749.818. hal ini menunjukkan bahwa penerimaan, biaya produksi dan pendapatan sangat bervariasi. Nilai rata-rata R/C ratio dari USAha industri jamu adalah sebesar 1,9 sehingga USAha industri jamu tersebut secara ekonomis menguntungkan dan dapat dilanjutkan.. ©2016 dipublikasikan oleh Agrimor
Euler number of Instanton Moduli space and Seiberg-Witten invariants
We show that a partition function of topological twisted N=4 Yang-Mills
theory is given by Seiberg-Witten invariants on a Riemannian four manifolds
under the condition that the sum of Euler number and signature of the four
manifolds vanish. The partition function is the sum of Euler number of
instanton moduli space when it is possible to apply the vanishing theorem. And
we get a relation of Euler number labeled by the instanton number with
Seiberg-Witten invariants, too. All calculation in this paper is done without
assuming duality.Comment: LaTeX, 34 page
Instanton Number of Noncommutative U(n) gauge theory
We show that the integral of the first Pontrjagin class is given by an
integer and it is identified with instanton number of the U(n) gauge theory on
noncommutative . Here the dimension of the vector space that
appear in the ADHM construction is called Instanton number. The calculation is
done in operator formalism and the first Pontrjagin class is defined by
converge series. The origin of the instanton number is investigated closely,
too.Comment: 6 color figures, 27 pages, some comments and references are
added,typos fixe
Observations and modeling of H_2 fluorescence with partial frequency redistribution in giant planet atmospheres
Partial frequency redistribution (PRD), describing the formation of the line
profile, has negligible observational effects for optical depths smaller than
~10^3, at the resolving power of most current instruments. However, when the
spectral resolution is sufficiently high, PRD modeling becomes essential in
interpreting the line shapes and determining the total line fluxes. We
demonstrate the effects of PRD on the H_2 line profiles observed at high
spectral resolution by the Far-Ultraviolet Spectroscopic Explorer (FUSE) in the
atmospheres of Jupiter and Saturn. In these spectra, the asymmetric shapes of
the lines in the Lyman (v"- 6) progression pumped by the solar Ly-beta are
explained by coherent scattering of the photons in the line wings. We introduce
a simple computational approximation to mitigate the numerical difficulties of
radiative transfer with PRD, and show that it reproduces the exact radiative
transfer solution to better than 10%. The lines predicted by our radiative
transfer model with PRD, including the H_2 density and temperature distribution
as a function of height in the atmosphere, are in agreement with the line
profiles observed by FUSE. We discuss the observational consequences of PRD,
and show that this computational method also allows us to include PRD in
modeling the continuum pumped H_2 fluorescence, treating about 4000 lines
simultaneously.Comment: 17 pages, accepted for publication in Ap
Structure of MnO nanoparticles embedded into channel-type matrices
X-ray diffraction experiments were performed on MnO confined in mesoporous
silica SBA-15 and MCM-41 matrices with different channel diameters. The
measured patterns were analyzed by profile analysis and compared to numerical
simulations of the diffraction from confined nanoparticles. From the lineshape
and the specific shift of the diffraction reflections it was shown that the
embedded objects form ribbon-like structures in the SBA-15 matrices with
channels diameters of 47-87 {\AA}, and nanowire-like structures in the MCM-41
matrices with channels diameters of 24-35 {\AA}. In the latter case the
confined nanoparticles appear to be narrower than the channel diameters. The
physical reasons for the two different shapes of the confined nanoparticles are
discussed.Comment: 8 pages, including 9 postscript figures, uses revtex4.cl
X-Ray/Ultraviolet Observing Campaign of the Markarian 279 Active Galactic Nucleus Outflow: a close look at the absorbing/emitting gas with Chandra-LETGS
We present a Chandra-LETGS observation of the Seyfert 1 galaxy Mrk 279. This
observation was carried out simultaneously with HST-STIS and FUSE, in the
context of a multiwavelength study of this source. The Chandra pointings were
spread over ten days for a total exposure time of ~360 ks. The spectrum of
Mrk279 shows evidence of broad emission features, especially at the wavelength
of the OVII triplet. We quantitatively explore the possibility that this
emission is produced in the broad line region (BLR). We modeled the broad UV
emission lines seen in the FUSE and HST-STIS spectra following the ``locally
optimally emitting cloud" approach. We find that the X-ray lines luminosity
derived from the best fit BLR model can match the X-ray features, suggesting
that the gas producing the UV lines is sufficient to account also for the X-ray
emission. The spectrum is absorbed by ionized gas whose total column density is
~5x10^{20} cm^{-2}. The absorption spectrum can be modeled by two distinct gas
components (log xi ~ 0.47 and 2.49, respectively) both showing a significant
outflow velocity. However, the data allow also the presence of intermediate
ionization components. The distribution of the column densities of such extra
components as a function of the ionization parameter is not consistent with a
continuous, power law-like, absorber, suggesting a complex structure for the
gas outflow for Mrk 279 (abridged).Comment: 16 pages, 12 figures. To appear in A&
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