587 research outputs found
The Black Hole in the Compact, High-dispersion Galaxy NGC 1271
Located in the Perseus cluster, NGC 1271 is an early-type galaxy with a small
effective radius of 2.2 kpc and a large stellar velocity dispersion of 276 km/s
for its K-band luminosity of 8.9x10^{10} L_sun. We present a mass measurement
for the black hole in this compact, high-dispersion galaxy using observations
from the integral field spectrograph NIFS on the Gemini North telescope
assisted by laser guide star adaptive optics, large-scale integral field unit
observations with PPAK at the Calar Alto Observatory, and Hubble Space
Telescope WFC3 imaging observations. We are able to map out the stellar
kinematics on small spatial scales, within the black hole sphere of influence,
and on large scales that extend out to four times the galaxy's effective
radius. We find that the galaxy is rapidly rotating and exhibits a sharp rise
in the velocity dispersion. Through the use of orbit-based stellar dynamical
models, we determine that the black hole has a mass of (3.0^{+1.0}_{-1.1}) x
10^9 M_sun and the H-band stellar mass-to-light ratio is 1.40^{+0.13}_{-0.11}
M_sun/L_sun (1-sigma uncertainties). NGC 1271 occupies the sparsely-populated
upper end of the black hole mass distribution, but is very different from the
Brightest Cluster Galaxies (BCGs) and giant elliptical galaxies that are
expected to host the most massive black holes. Interestingly, the black hole
mass is an order of magnitude larger than expectations based on the galaxy's
bulge luminosity, but is consistent with the mass predicted using the galaxy's
bulge stellar velocity dispersion. More compact, high-dispersion galaxies need
to be studied using high spatial resolution observations to securely determine
black hole masses, as there could be systematic differences in the black hole
scaling relations between these types of galaxies and the BCGs/giant
ellipticals, thereby implying different pathways for black hole and galaxy
growth.Comment: accepted for publication in Ap
Scattering and radiation problems of arbitrarily shaped conducting bodies above the ground plane
Cataloged from PDF version of article.A method of moment solution is applied for the scattering and radiation problems
of arbitrarily shaped conducting bodies placed close to an infinite ground plane.
An equivalent problem is produced by using image theory and solved by two
methods. Free-space Green’s function is used for the first method, and modified
free-space Green’s function is used for the second. The conducting bodies excited
with either an incident plane-wave or a delta-gap source. Moreover, the definition
method of the basis functions is explained when multiple unknowns occur at a
single edge.Yıldırım, Cemal C.M.S
The structural and dynamical properties of compact elliptical galaxies
Dedicated photometric and spectroscopic surveys have provided unambiguous
evidence for a strong stellar mass-size evolution of galaxies within the last
10 Gyr. The likely progenitors of today's most massive galaxies are remarkably
small, disky, passive and have already assembled much of their stellar mass at
redshift z=2. An in-depth analysis of these objects, however, is currently not
feasible due to the lack of high-quality, spatially-resolved photometric and
spectroscopic data. In this paper, we present a sample of nearby compact
elliptical galaxies (CEGs), which bear resemblance to the massive and quiescent
galaxy population at earlier times. Hubble Space Telescope (HST) and wide-field
integral field unit (IFU) data have been obtained, and are used to constrain
orbit-based dynamical models and stellar population synthesis (SPS) fits, to
unravel their structural and dynamical properties. We first show that our
galaxies are outliers in the present-day stellar mass-size relation. They are,
however, consistent with the mass-size relation of compact, massive and
quiescent galaxies at redshift z=2. The compact sizes of our nearby galaxies
imply high central stellar mass surface densities, which are also in agreement
with the massive galaxy population at higher redshift, hinting at strong
dissipational processes during their formation. Corroborating evidence for a
largely passive evolution within the last 10 Gyr is provided by their orbital
distribution as well as their stellar populations, which are difficult to
reconcile with a very active (major) merging history. This all supports that we
can use nearby CEGs as local analogues of the high-redshift, massive and
quiescent galaxy population, thus providing additional constraints for models
of galaxy formation and evolution.Comment: 33 pages, 27 figures and 20 tables (with most of the tables provided
as online-only supporting information). Accepted for publication in MNRA
The effect of propolis addition to the laying-hen diet on performance, serum lipid profile and liver fat rate
The aim of this study was to evaluate the effect of propolis (P) on
performance, egg quality parameters, serum lipid profile, some liver enzymes
and liver fat ratio. One-hundred-and-twenty Lohmann (LSL) laying hens were divided into five
groups, and each group consisted of six subgroups. The control group was fed
basal diet. The other groups were fed high-energy (HE) diets to induce fatty
liver syndrome, and 0, 100, 200 and 300 mg kg−1 of propolis were supplemented with
high-energy feeds. During the 8-week trial, feed and water
were given ad libitum.
It was determined that egg production and feed conversion ratio were
decreased in the high-energy feed group without the addition of propolis.
The highest egg production was found in HE + 100 and HE + 200 mg kg−1 of P groups. It was found that liver fat ratios were higher in the group
fed with HE + 0 mg kg−1 of P feed (P<0.01) than other groups. But the
addition of P decreased the liver fat rate significantly. The highest very
low density lipoprotein (VLDL), triglyceride (TG) and low-density
lipoprotein (LDL) values were found for the HE + 0 mg kg−1 of P group. The
addition of 200 mg kg−1 of P to high-energy feed increased glutathione
(GSH), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase
(GPx) values.
In conclusion, high-energy feed adversely affected egg production and liver
fat ratio, but the addition of 100 or 200 mg kg−1 of propolis improved egg
production and decreased liver fat ratio.</p
Constraining the multi-scale dark-matter distribution in CASSOWARY 31 with strong gravitational lensing and stellar dynamics
We study the inner structure of the group-scale lens CASSOWARY 31 (CSWA 31)
by adopting both strong lensing and dynamical modeling. CSWA 31 is a peculiar
lens system. The brightest group galaxy (BGG) is an ultra-massive elliptical
galaxy at z = 0.683 with a weighted mean velocity dispersion of km s. It is surrounded by group members and several lensed arcs
probing up to ~150 kpc in projection. Our results significantly improve
previous analyses of CSWA 31 thanks to the new HST imaging and MUSE
integral-field spectroscopy. From the secure identification of five sets of
multiple images and measurements of the spatially-resolved stellar kinematics
of the BGG, we conduct a detailed analysis of the multi-scale mass distribution
using various modeling approaches, both in the single and multiple lens-plane
scenarios. Our best-fit mass models reproduce the positions of multiple images
and provide robust reconstructions for two background galaxies at z = 1.4869
and z = 2.763. The relative contributions from the BGG and group-scale halo are
remarkably consistent in our three reference models, demonstrating the
self-consistency between strong lensing analyses based on image position and
extended image modeling. We find that the ultra-massive BGG dominates the
projected total mass profiles within 20 kpc, while the group-scale halo
dominates at larger radii. The total projected mass enclosed within =
27.2 kpc is M. We find that CSWA
31 is a peculiar fossil group, strongly dark-matter dominated towards the
central region, and with a projected total mass profile similar to higher-mass
cluster-scale halos. The total mass-density slope within the effective radius
is shallower than isothermal, consistent with previous analyses of early-type
galaxies in overdense environments.Comment: 22 pages, 12 figures, 5 tables, submitted to Astronomy &
Astrophysics. We welcome the comments from reader
Relationship among expression of basic-fibroblast growth factor, MTDH/Astrocyte elevated gene-1, adenomatous polyposis coli, matrix metalloproteinase 9,and COX-2 markers with prognostic factors in prostate carcinomas
Background: The etiopathogenesis of prostate cancer (PC) is still not clear, but hormonal, genetic, and environmental factors are thought to play a role in the tumor pathogenesis. Astrocyte elevated gene-1(AEG-1) as a novel transmembrane protein is predominantly located in the perinuclear region and endoplasmic reticulum. It has been found that AEG-1 upregulation increases the invasive ability of glioma and prostate cancer. Basic fibroblast growth factor (bFGF), matrix metalloproteinase-9 (MMP-9), cyclooxygenases-2 (COX-2), and adenomatous polyposis coli (APC) are very important in tumor progression as well. Materials and Methods: This study included 97 radical prostatectomy specimens. IHC stains for bFGF, MMP-9, COX-2, APC, and AEG-1 were performed on the tissue microarray using standard procedures. For each patient, the age, Gleason score, tumor volume, lymphovascular invasion, lymph node metastasis, surgical margin, and the invasion of vesiculoseminalis areas were assessed. Analyses were performed using the statistical PASW (ver. 18). Results: Statistically significant positive relationships were found MMP-9 and COX-2 (r = 0.242 and P = 0.017), between MMP-9 and APC (r = 0.207 and P = 0.043), and between bFGF and AEG-1 (r = 0.295 and P = 0.004). However, the relationships between age and staining results and tumor volume and staining results were not found to be significant. Although a positive correlation was found between the Gleason score and tumor volume and the Gleason score and age (r = 0.415 and P = 0.0001; r = 0.246 and P = 0.015, respectively), we did not find a statistically significant relationship between other stains and other prognostic parameters (lymphovascular invasion, lymph node metastasis, surgical margin, or vesiculoseminalis invasion). Conclusion:The relationships we found between MMP-9 and COX-2, between MMP-9, and APC and between bFGF and AEG-1 as independent prognostic parameters could be helpful in the development of new therapeutic procedures.Keywords: Adenomatous polyposis coli, astrocyte elevated gene‑1, basic fibroblast growth factor, cyclooxygenases‑2, matrix metalloproteinase‑9, prognostic parameters, prostate adenocarcinomasNigerian Journal of Clinical Practice • Oct-Dec 2013 • Vol 16 • Issue
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