587 research outputs found

    The Black Hole in the Compact, High-dispersion Galaxy NGC 1271

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    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

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    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

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    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

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    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&lt;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

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    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 σ=432±31\sigma = 432 \pm 31 km s−1^{-1}. 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 ReffR_{eff} = 27.2 kpc is 1.10−0.04+0.02×10131.10_{-0.04}^{+0.02} \times 10^{13} M⊙_\odot. 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

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    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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