Página 1 dos resultados de 195974 itens digitais encontrados em 0.231 segundos

Preferential Expansion of Vγ9-JγP/Vδ2-Jδ3 γδ T Cells in Nasal T-Cell Lymphoma and Chronic Active Epstein-Barr Virus Infection

Oyoshi, Michiko K.; Nagata, Hiroshi; Kimura, Nobuhiro; Zhang, Yu; Demachi, Ayako; Hara, Toshiro; Kanegane, Hirokazu; Matsuo, Yoshinobu; Yamaguchi, Tomohiro; Morio, Tomohiro; Hirano, Atsuyoshi; Shimizu, Norio; Yamamoto, Kohtaro
Fonte: American Society for Investigative Pathology Publicador: American Society for Investigative Pathology
Tipo: Artigo de Revista Científica
Publicado em /05/2003 Português
Relevância na Pesquisa
46.139414%
We recently established an Epstein-Barr virus (EBV)-positive γδ T-cell line from a nasal T/natural killer (NK)-cell lymphoma (Nagata H, Konno A, Kimura N, Zhang Y, Kimura M, Demachi A, Sekine T, Yamamoto K, Shimizu N: Characterization of novel natural killer (NK)-cell and γδ T-cell lines established from primary lesions of nasal T/NK-cell lymphomas associated with the Epstein-Barr virus. Blood 2001, 97:708–713). Subsequently, we established two novel EBV-positive γδ T-cell lines from the peripheral blood of patients with chronic active EBV infection. Analysis of the terminal repeat of EBV showed that the three cell lines consisted of monoclonal populations, and flow cytometry showed that they had a common phenotype of γδ T cells: CD3+ CD4− CD8− CD16− CD19− CD56+ CD57− HLA-DR+ T-cell receptor (TCR) αβ− TCR γδ+. Analysis for the expression of TCR by flow cytometry showed that all three cell lines were Vγ9+/Vδ2+, but negative for VγI, Vδ1, or Vδ3 TCR. Southern blot analysis for TCR genes showed that the three cell lines had a common rearrangement of Vγ9-JγP and Jδ3 genes. Polymerase chain reaction and sequence analysis of the junction between Vδ and Jδ genes revealed that the Jδ3 genes were rearranged with the Vδ2 genes. In contrast...

Warm and Dense Molecular Gas in the N159 Region: 12CO J=4–3 and 13CO J=3–2 Observations with NANTEN2 and ASTE

Bernard, Jean-Philippe; Rubio, Mónica; Yamamoto, Hiroaki; Yamaguchi, Nobuyuki; Wong, Tony; Whitney, Barbara; Tatematsu, Ken’ichi; Kawamura, Akiko; Bertoldi, Frank; Ikeda, Masafumi; Stutzki, Jürgen; Klein, Uli; Benz, Arnold; Gordon, Karl D.; Burton, Mi
Fonte: Universidade do Chile Publicador: Universidade do Chile
Tipo: Artículo de revista
Português
Relevância na Pesquisa
46.20606%
New 12CO J=4–3 and 13CO J=3–2 observations of the N159 region, an active site of massive star formation in the Large Magellanic Cloud, have been made with the NANTEN2 and ASTE sub-mm telescopes, respectively. The 12CO J=4–3 distribution is separated into three clumps, each associated with N159W, N159E and N159S. These new measurements toward the three clumps are used in coupled calculations of molecular rotational excitation and line radiation transfer, along with other transitions of the 12CO J=1–0, J=2–1, J=3–2, and J=7–6 as well as the isotope transitions of 13CO J=1–0, J=2–1, J=3–2, and J=4–3. The 13CO J=3–2 data are newly taken for the present work. The temperatures and densities are determined to be 70-80K and 3×103 cm−3 in N159W and N159E and 30K and 1.6×103 cm−3 in N159S. Observed 12CO J=2–1 and 12CO J=1–0 intensities toward N159W and N159E are weaker than expected from calculations of uniform temperature and density, suggesting that low-excitation foreground gas causes self-absorption. These results are compared with the star formation activity based on the data of young stellar clusters and HII regions as well as the mid-infrared emission obtained with the Spitzer MIPS. The N159E clump is associated with embedded cluster(s) as observed at 24 μm by the Spitzer MIPS and the derived high temperature...

DENSE CLUMPS IN GIANT MOLECULAR CLOUDS IN THE LARGE MAGELLANIC CLOUD: DENSITY AND TEMPERATURE DERIVED FROM (13)CO(J=3-2) OBSERVATIONS

Fukui, Yasuo; Kim, Sungeun; Hasegawa, Tetsuo; Tanaka, Takanori; Ezawa, Hajime; Tatematsu, Ken’ichi; Kohno, Kotaro; Sakai, Takeshi; Kawamura, Akiko; Torii, Kazufumi; Muraoka, Kazuyuki; Sorai, Kazuo; Onishi, Toshikazu; Takekoshi, Tatsuya; Moribe, Nayuta;
Fonte: IOP PUBLISHING LTD Publicador: IOP PUBLISHING LTD
Tipo: Artículo de revista
Português
Relevância na Pesquisa
46.17513%
Artículo de publicación ISI; In order to precisely determine the temperature and density of molecular gas in the Large Magellanic Cloud, we made observations of the optically thin (13)CO(J = 3-2) transition using the ASTE 10 m telescope toward nine peaks where (12)CO(J = 3-2) clumps were previously detected with the same telescope. The molecular clumps include those in giant molecular cloud (GMC) Types I (with no signs of massive star formation), II ( with H II regions only), and III (with H II regions and young star clusters). We detected (13)CO(J = 3-2) emission toward all the peaks and found that their intensities are 3-12 times lower than those of (12)CO(J = 3-2). We determined the intensity ratios of (12)CO(J = 3-2) to (13)CO(J = 3-2), R(3-2)(12/13), and (13)CO(J = 3-2) to (13)CO(J = 1-0), R(3-2/1-0)(13), at 45 '' resolution. These ratios were used in radiative transfer calculations in order to estimate the temperature and density of the clumps. The clumps have a kinetic temperature range of T(kin) = 15-200 K and a molecular hydrogen gas density range of n(H(2)) = 8 x 10(2)-7 x 10(3) cm(-3). We confirmed that the higher density clumps have higher kinetic temperature and that the lower density clumps have lower kinetic temperature to better accuracy than in previous work. The kinetic temperature and density increase generally from a Type I GMC to a Type III GMC. We interpret that this difference reflects an evolutionary trend of star formation in molecular clumps. The R(3-2/1-0)(13) and kinetic temperature of the clumps are well correlated with the Ha flux...

Dense Clumps in Giant Molecular Clouds in the Large Magellanic Cloud: Density and Temperature Derived from $^{13}$CO($J=3-2$) Observations

Minamidani, Tetsuhiro; Tanaka, Takanori; Mizuno, Yoji; Mizuno, Norikazu; Kawamura, Akiko; Onishi, Toshikazu; Hasegawa, Tetsuo; Tatematsu, Ken'ichi; Takekoshi, Tatsuya; Sorai, Kazuo; Moribe, Nayuta; Torii, Kazufumi; Sakai, Takeshi; Muraoka, Kazuyuki; Tanak
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 22/12/2010 Português
Relevância na Pesquisa
46.17513%
In order to precisely determine temperature and density of molecular gas in the Large Magellanic Cloud, we made observations of optically thin $^{13}$CO($J=3-2$) transition by using the ASTE 10m telescope toward 9 peaks where $^{12}$CO($J=3-2$) clumps were previously detected with the same telescope. The molecular clumps include those in giant molecular cloud (GMC) Types I (with no signs of massive star formation), II (with HII regions only), and III (with HII regions and young star clusters). We detected $^{13}$CO($J=3-2$) emission toward all the peaks and found that their intensities are 3 -- 12 times lower than those of $^{12}$CO($J=3-2$). We determined the intensity ratios of $^{12}$CO($J=3-2$) to $^{13}$CO($J=3-2$), $R^{12/13}_{3-2}$, and $^{13}$CO($J=3-2$) to $^{13}$CO($J=1-0$), $R^{13}_{3-2/1-0}$, at 45$\arcsec$ resolution. These ratios were used for radiative transfer calculations in order to estimate temperature and density of the clumps. The parameters of these clumps range kinetic temperature $T\mathrm{_{kin}}$ = 15 -- 200 K, and molecular hydrogen gas density $n(\mathrm{H_2})$ = 8$\times 10^2$ -- 7$\times 10^3$ cm$^{-3}$. We confirmed that the higher density clumps show higher kinetic temperature and that the lower density clumps lower kinetic temperature at a better accuracy than in the previous work. The kinetic temperature and density increase generally from a Type I GMC to a Type III GMC. We interpret that this difference reflects an evolutionary trend of star formation in molecular clumps. The $R^{13}_{3-2/1-0}$ and kinetic temperature of the clumps are well correlated with H$\alpha$ flux...

The Large-scale J=3-2 and J=2-1 CO Emission from M17 and its Implications for Extragalactic CO Observations

Wilson, C. D.; Howe, J. E.; Balogh, M. L.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 11/01/1999 Português
Relevância na Pesquisa
56.102695%
We observed a 10x20 pc region of the molecular cloud M17 in the 12CO and 13CO J=3-2 and J=2-1 transitions to determine their global behavior and to assess the reliability of using ratios of CO line intensities integrated over an entire cloud to determine the physical conditions within the cloud. Both the 12CO/13CO J=2-1 and J=3-2 line ratios correlate with the 13CO integrated intensity, with smaller line ratios observed at locations with large integrated intensities. This correlation is likely due to variations in the column density from one position to another within M17. The 12CO and 13CO (J=3-2/J=2-1) line ratios show no significant variation from place to place within M17, even on the peak of the photon-dominated region. A Large Velocity Gradient analysis of globally averaged line ratios gives results in reasonable agreement with the results obtained for individual lines-of-sight through the cloud, which suggests that the typical physical conditions in a molecular cloud can be determined using CO line ratios integrated over the entire cloud. There appears to be a clear trend of increasing 12CO/13CO J=2-1 and J=3-2 line ratios as one moves from Galactic molecular cloud cores to entire Galactic molecular clouds to normal galaxies. The most likely explanation of the high line ratios for normal galaxies is a significant contribution to the CO emission by low column density material...

The Skyrme model predictions for the ${\bf 27}_{J=3/2}$ mass spectrum and the ${\bf 27}_{3/2}$-$\bar{\bf 10}$ mass splittings

Duplancic, G.; Pasagic, H.; Trampetic, J.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
56.030635%
The ${\bf 27}_{J=3/2}$-plet mass spectrum and the ${\bf 27}_{3/2}$-$\bar{\bf 10}$ mass splittings are computed in the framework of the minimal SU(3)$_f$ extended Skyrme model. As functions of the Skyrme charge $e$ and the SU(3)$_f$ symmetry breaking parameters the predictions are presented in tabular form. The predicted mass splitting ${\bf 27}_{3/2}$-$\bar{\bf 10}$ is the smallest among all SU(3)$_f$ baryonic multiplets.; Comment: 4 pages, 2 tables, version to appear in Phys. Rev. D

The JCMT Nearby Galaxies Legacy Survey V: The CO(J=3-2) Distribution and Molecular Outflow in NGC~4631

Irwin, Judith A.; Wilson, C. D.; Wiegert, T.; Bendo, G. J.; Warren, B. E.; Wang, Q. D.; Israel, F. P.; Serjeant, S.; Knapen, J. H.; Brinks, E.; Tilanus, R. P. J.; van der Werf, P.; Muehle, S.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 24/08/2010 Português
Relevância na Pesquisa
56.083003%
We have made the first map of CO(J=3-2) emission covering the disk of the edge-on galaxy, NGC~4631, which is known for its spectacular gaseous halo. The strongest emission, which we model with a Gaussian ring,occurs within a radius of 5 kpc. Weaker disk emission is detected out to radii of 12 kpc, the most extensive molecular component yet seen in this galaxy. From comparisons with infrared data, we find that CO(J=3-2) emission more closely follows the hot dust component, rather than the cold dust,consistent with it being a good tracer of star formation. The first maps of $R_{3-2/1-0}$, H$_2$ mass surface density and SFE have been made for the inner 2.4 kpc radius region. Only 20\% of the SF occurs in this region and excitation conditions are typical of galaxy disks, rather than of central starbursts. The SFE suggests long gas consumption timescales ($>$ $10^9$ yr). The velocity field is dominated by a steeply rising rotation curve in the region of the central molecular ring followed by a flatter curve in the disk. A very steep gradient in the rotation curve is observed at the nucleus, providing the first evidence for a central concentration of mass: M$_{dyn}\,=\,5\,\times\,10^7$ M$_\odot$ within a radius of 282 pc. The velocity field shows anomalous features indicating the presence of molecular outflows; one of them is associated with a previously observed CO(J=1-0) expanding shell. Consistent with these outflows is the presence of a thick ($z$ up to $1.4$ kpc) CO(J=3-2) disk. We suggest that the interaction between NGC~4631 and its companion(s) has agitated the disk and also initiated star formation which was likely higher in the past than it is now. These may be necessary conditions for seeing prominent halos.; Comment: 21 pages...

A mapping study of L1174 with 13CO J=2-1 and 12CO J=3-2: star formation triggered by a Herbig Ae/Be star

Yuan, J. H.; Wu, Y.; Li, J. Z.; Yu, W.; Miller, M.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
56.05766%
We have carried out a comprehensive study of the molecular conditions and star-forming activities in dark cloud L1174 with multi-wavelength data. Mapping observations of L1174 in $^{13}$CO $J=2-1$ and $^{12}$CO $J=3-2$ were performed using the KOSMA 3-meter telescope. Six molecular cores with masses ranging from 5 to 31 $M_\odot$ and sizes ranging from 0.17 to 0.39 pc are resolved. Large area ahead of a Herbig Be star, HD 200775, is in expanding and core 1 is with collapse signature. Large line widths of $^{13}$CO $J=2-1$ indicate the ubiquity of turbulent motions in this region. Spectra of $^{12}$CO $J=3-2$ prevalently show conspicuously asymmetric double-peaked profiles. In a large area, red-skewed profiles are detected and suggestive of a scenario of global expansion. There is a large cavity around the Herbig Be star HD 200775, the brightest star in L1174. The gas around the cavity has been severely compressed by the stellar winds from HD 200775. Feedbacks from HD 200775 may have helped form the molecular cores around the cavity. Seventeen 2MASS potential young stellar objects were identified according to their 2MASS colour indices. The spatial distribution of the these 2MASS sources indicates that some of them have a triggered origin. All these suggest that feedbacks from a Herbig Ae/Be star may also have the potential to trigger star forming activities.; Comment: 13 pages...

A CO J=3-2 map of M51 with HARP-B: Radial properties of the spiral structure

Vlahakis, C.; van der Werf, P.; Israel, F. P.; Tilanus, R. P. J.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 27/04/2013 Português
Relevância na Pesquisa
56.17908%
We present the first complete CO J=3-2 map of the nearby grand-design spiral galaxy M51 (NGC 5194), at a spatial resolution of ~600 pc, obtained with the HARP-B instrument on the James Clerk Maxwell Telescope. The map covers the entire optical galaxy disk and out to the companion NGC 5195, with CO J=3-2 emission detected over an area of ~9'x6' (~21x14 kpc). We describe the CO J=3-2 integrated intensity map and combine our results with maps of CO J=2-1, CO J=1-0 and other data from the literature to investigate the variation of the molecular gas, atomic gas and polycyclic aromatic hydrocarbon (PAH) properties of M51 as a function of distance along the spiral structure on sub-kpc scales. We find that for the CO J=3-2 and CO J=2-1 transitions there is a clear difference between the variation of arm and inter-arm emission with galactocentric radius, with the inter-arm emission relatively constant with radius and the contrast between arm and inter-arm emission decreasing with radius. For CO J=1-0 and HI the variation with radius shows a similar trend for the arm and inter-arm regions, and the arm-inter-arm contrast appears relatively constant with radius. We investigate the variation of CO line ratios (J=3-2/2-1, J=2-1/1-0 and J=3-2/1-0) as a function of distance along the spiral structure. Line ratios are consistent with the range of typical values for other nearby galaxies in the literature. The highest CO J=3-2/2-1 line ratios are found in the central ~1 kpc and in the spiral arms and the lowest line ratios in the inter-arm regions.We find no clear evidence of a trend with radius for the spiral arms but for the inter-arm regions there appears to be a trend for all CO line ratios to increase with radius. We find a strong relationship between the ratio of CO J=3-2 intensity to stellar continuum-subtracted 8mu PAH surface brightness and the CO J=3-2 intensity that appears to vary with radius.; Comment: 26 pages...

Ground-state phases of the frustrated spin-1/2 $J_{1}$--$J_{2}$--$J_{3}$ Heisenberg ferromagnet ($J_{1}<0$) on the honeycomb lattice with $J_{3}=J_{2}>0$

Li, P. H. Y.; Bishop, R. F.; Farnell, D. J. J.; Richter, J.; Campbell, C. E.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
56.1409%
We study the ground-state (gs) properties of the frustrated spin-1/2 $J_{1}$--$J_{2}$--$J_{3}$ Heisenberg model on a honeycomb lattice with ferromagnetic (FM) nearest-neighbor ($J_{1}=-1$) exchange and frustrating antiferromagnetic (AFM) next-nearest-neighbor ($J_{2}>0$) and next-next-nearest-neighbor ($J_{3}>0$) exchanges, for the case $J_{3}=J_{2}$. We use the coupled cluster method in high orders of approximation, complemented by the exact diagonalization of a lattice with 32 sites, and calculate the gs energy, magnetic order parameter, and spin-spin correlation functions. We find a quantum phase transition between regions characterized by FM order and a form of AFM ("striped") collinear order at $J^{c}_{2} \approx 0.1095 \pm 0.0005$. We compare results for the FM case (with $J_{1}=-1$) to previous results for the corresponding AFM case (with $J_{1}=+1$). While the magnetic order parameters behave similarly for the FM and the AFM models for large values of the frustration parameter $J_{2}$, there are considerable differences between them for $J_{2}/|J_{1}| \lesssim 0.6$. For example, the quasiclassical collinear magnetic long-range order for the AFM model (with $J_{1}=+1$) breaks down at $J^{c_{2}}_{2} \approx 0.60$, whereas the "equivalent" point for the FM model (with $J_{1}=-1$) occurs at $J^{c}_{2} \approx 0.11$. Unlike in the AFM model (with $J_{1}=+1$)...

An investigation of the quantum $J_1-J_2-J_3$ model on the honeycomb lattice

Fouet, J. B.; Sindzingre, P.; Lhuillier, C.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 28/01/2001 Português
Relevância na Pesquisa
56.048447%
We have investigated the quantum $J_1-J_2-J_3$ model on the honeycomb lattice with exact diagonalizations and linear spin-wave calculations for selected values of $J_{2}/J_{1}$, $J_{3}/J_{1}$ and antiferromagnetic ($J_{1}>0$) or ferromagnetic ($J_{1}<0$) nearest neighbor interactions. We found a variety of quantum effects: "order by disorder" selection of a N{\'e}el ordered ground-state, good candidates for non-classical ground-states with dimer long range order or spin-liquid like. The purely antiferromagnetic Heisenberg model is confirmed to be N{\'e}el ordered. Comparing these results with those observed on the square and triangular lattices, we enumerate some conjectures on the nature of the quantum phases in the isotropic models.; Comment: 14 pages, 22 Postscript figures, uses svjour.cls and svepj.clo, submitted to European Physical Journal B: condensed matter physic

Phase diagram of a frustrated Heisenberg antiferromagnet on the honeycomb lattice: the $J_{1}$--$J_{2}$--$J_{3}$ model

Li, P. H. Y.; Bishop, R. F.; Farnell, D. J. J.; Campbell, C. E.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 11/04/2012 Português
Relevância na Pesquisa
56.17639%
We use the coupled cluster method in high orders of approximation to make a comprehensive study of the ground-state (GS) phase diagram of the spin-1/2 $J_{1}$--$J_{2}$--$J_{3}$ model on a two-dimensional honeycomb lattice with antiferromagnetic (AFM) interactions up to third-nearest neighbors. Results are presented for the GS energy and the average local on-site magnetization. With the nearest-neighbor coupling strength $J_{1} \equiv 1$ we find four magnetically ordered phases in the parameter window $J_{2},J_{3} \in [0,1]$, namely the N\'{e}el (N), striped (S), and anti-N\'{e}el (aN) collinear AFM phases, plus a spiral phase. The aN phase appears as a stable GS phase in the classical version of the model only for values $J_{3}<0$. Each of these four ordered phases shares a boundary with a disordered quantum paramagnetic (QP) phase, and at several widely separated points on the phase boundaries the QP phase has an infinite susceptibility to plaquette valence-bond crystalline order. We identify all of the phase boundaries with good precision in the parameter window studied, and we find three tricritical quantum critical points therein at: (a) $(J_{2}^{c_1},J_{3}^{c_1})=(0.51 \pm 0.01,0.69 \pm 0.01)$ between the N, S, and QP phases; (b) $(J_{2}^{c_2}...

12CO(J=2->1) and CO(J=3->2) observations of Virgo Cluster spiral galaxies with the KOSMA telescope: global properties

Hafok, H.; Stutzki, J.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 25/11/2002 Português
Relevância na Pesquisa
56.035415%
We present 12CO(J=2->1) and CO(J=3->2) observations of quiescent Virgo Cluster spiral galaxies with the KOSMA 3m submm telescope. The beam sizes of 80" at 345 GHz and 120" at 230 GHz are well suited for the investigation of global properties of Virgo Cluster galaxies. The observed sample was selected based on previous 12CO(J=1->0) detections by Stark et al. (1986), performed with the AT&T Bell Laboratory 7m telescope (beam size 100"). We were able to detect 18 spiral galaxies in 12CO(2->1) and 16 in 12CO(3->2). Beam matched observations of the lowest three 12CO transitions allow us to compare our results with previous high spatial resolution studies of (moderate) starburst galaxies and galactic core regions. We discuss the global excitation conditions of the ISM in these quiescent spiral galaxies. The resulting CO (3--2)/(1--0) integrated line ratios vary over a relatively narrow range of values from 0.35 to 0.14 (on a K km/s-scale) with increasing CO (2--1)/(1--0) ratio (from 0.5 to 1.1). The line ratios between the three lowest rotational transitions of CO cannot be fitted by any radiative transfer model with a single source component. A two-component model, assuming a warm, dense nuclear and a cold, less dense disc component allows us to fit the observed line ratios for most of the galaxies individually by selecting suitable parameters. The two-component model...

SMA CO(J=3-2) interferometric observations of the central region of M51

Matsushita, S.; Sakamoto, K.; Kuo, C. -Y.; Hsieh, P. -Y.; Dinh-V-Trung; Mao, R. -Q.; Iono, D.; Peck, A. B.; Wiedner, M. C.; Liu, S. -Y.; Ohashi, N.; Lim, J.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 30/07/2004 Português
Relevância na Pesquisa
56.062554%
We present the first interferometric CO(J=3-2) observations (beam size of 3.9"x1.6" or 160pc x 65pc) with the Submillimeter Array (SMA) toward the center of the Seyfert 2 galaxy M51. The image shows a strong concentration at the nucleus and weak emission from the spiral arm to the northwest. The integrated intensity of the central component in CO(J=3-2) is almost twice as high as that in CO(J=1-0), indicating that the molecular gas within an ~80 pc radius of the nucleus is warm (>~100 K) and dense (~10^4 cm^-3). Similar intensity ratios are seen in shocked regions in our Galaxy, suggesting that these gas properties may be related to AGN or starburst activity. The central component shows a linear velocity gradient (~1.4 km/s/pc) perpendicular to the radio continuum jet, similar to that seen in previous observations and interpreted as a circumnuclear molecular disk/torus around the Seyfert 2 nucleus. In addition, we identify a linear velocity gradient (~0.7 km/s/pc) along the jet. Judging from the energetics, the velocity gradient can be explained by supernova explosions or energy and momentum transfer from the jet to the molecular gas via interaction, which is consistent with the high intensity ratio.; Comment: 12 pages, 3 figures, accepted for publication in ApJL

High resolution observations of HCN and HCO+ J=3-2 in the disk and outflow of Mrk231 -Detection of vibrationally excited HCN in the warped nucleus

Aalto, S.; Garcia-Burillo, S.; Muller, S.; Winters, J. M.; Gonzalez-Alfonso, E.; van der Werf, P.; Henkel, C.; Costagliola, F.; Neri, R.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 10/11/2014 Português
Relevância na Pesquisa
56.019805%
We obtained high resolution (0."25 to 0."90) observations of HCN and HCO+ J=3-2 of the ultraluminous QSO galaxy Mrk231 with the IRAM Plateau de Bure Interferometer. We find luminous HCN and HCO+ 3-2 emission in the main disk and we detect compact (r<90 pc) vibrationally excited HCN 3-2, v2=1f emission centred on the nucleus. The velocity field of the vibrationally excited HCN is strongly inclined (PA=155 deg.) compared to the east-west rotation of the main disk. The nuclear molecular mass is estimated to 8e8 Msun with an average N(H2)of 1.2e24 cm-2. Prominent, spatially extended (>350 pc) line wings are found for HCN 3-2 with velocities +-750 km/s. Line ratios indicate that the emission is emerging in dense gas n=1e4 - 5e5 cm-3 of elevated HCN abundance X(HCN)=1e-8 to 1e-6. High X(HCN) also allows for the emission to originate in gas of more moderate density. We tentatively detect nuclear emission from the reactive ion HOC+ with HCO+/HOC+=10-20. The HCN v2=1f line emission is consistent with the notion of a hot, dusty, warped inner disk of Mrk231 where the v2=1f line is excited by bright mid-IR 14 micron continuum. We estimate the vibrational temperature T_vib to 200-400 K. We propose that 50% of the main HCN emission may have its excitation affected by the radiation field through IR pumping of the vibrational ground state. The HCN emission in the line wings...

Probing Circumnuclear Environments with the HCN(J = 3-2) and HCO+(J = 3-2) lines: Case of NGC 1097

Hsieh, Pei-Ying; Ho, Paul T. P.; Kohno, Kotaro; Hwang, Chorng-Yuan; Matsushita, Satoki
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 01/01/2012 Português
Relevância na Pesquisa
46.206885%
We present the first interferometric HCN(J = 3-2) and HCO+(J = 3-2) maps in the circumnuclear region of NGC 1097, obtained with the Submillimeter Array. The goal is to study the characteristics of the dense gas associated with the starburst ring/Seyfert nucleus. With these transitions, we suppress the diffuse low density emission in the nuclear region. We detect and resolve the individual compact giant molecular cloud associations (GMAs) in the 1.4 kpc circumnuclear starburst ring and within the 350 pc nuclear region. The nucleus is brighter than the ring in both lines, and contributes to ~20% and ~30% to the total detected HCO+(J = 3-2) and HCN(J = 3-2) flux, within the central 1.4 kpc. The intensity ratios of HCN(J = 3-2)/HCO+(J = 3-2) are roughly unity in the GMAs of the starburst ring. However, this ratio is up to ~2 in the nuclear region. From the HCN(J = 3-2)/HCN(J = 1-0) ratio of <0.2 in the nucleus, we infer that the nuclear HCN(J = 3-2) emission might be optically thin. The HCO+(J = 3-2) and HCN(J = 3-2) show correlations with 12CO(J = 3-2) and the 24{\mu}m emission. The tight correlations of HCN(J = 3-2), HCO+(J = 3-2) and 24{\mu}m emission in the starburst ring suggest that the dense molecular gas and the dust are from the same origins of star forming regions. On the other hand...

Sub-millimeter Observations of Giant Molecular Clouds in the Large Magellanic Cloud: Temperature and Density as Determined from J=3-2 and J=1-0 transitions of CO

Minamidani, T.; Mizuno, N.; Mizuno, Y.; Kawamura, A.; Onishi, T.; Hasegawa, T.; Tatematsu, K.; Ikeda, M.; Moriguchi, Y.; Yamaguchi, N.; Ott, J.; Wong, T.; Muller, E.; Pineda, J. L.; Hughes, A.; Staveley-Smith, L.; Klein, U.; Mizuno, A.; Nikolić, S.; Boot
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 23/10/2007 Português
Relevância na Pesquisa
56.090854%
We have carried out sub-mm 12CO(J=3-2) observations of 6 giant molecular clouds (GMCs) in the Large Magellanic Cloud (LMC) with the ASTE 10m sub-mm telescope at a spatial resolution of 5 pc and very high sensitivity. We have identified 32 molecular clumps in the GMCs and revealed significant details of the warm and dense molecular gas with n(H2) $\sim$ 10$^{3-5}$ cm$^{-3}$ and Tkin $\sim$ 60 K. These data are combined with 12CO(J=1-0) and 13CO(J=1-0) results and compared with LVG calculations. We found that the ratio of 12CO(J=3-2) to 12CO(J=1-0) emission is sensitive to and is well correlated with the local Halpha flux. We interpret that differences of clump propeties represent an evolutionary sequence of GMCs in terms of density increase leading to star formation.Type I and II GMCs (starless GMCs and GMCs with HII regions only, respectively) are at the young phase of star formation where density does not yet become high enough to show active star formation and Type III GMCs (GMCs with HII regions and young star clusters) represents the later phase where the average density is increased and the GMCs are forming massive stars. The high kinetic temperature correlated with \Halpha flux suggests that FUV heating is dominant in the molecular gas of the LMC.; Comment: 74 pages...

CO(J=3-2) On-the-fly Mapping of the Nearby Spiral Galaxies NGC 628 and NGC 7793: Spatially-resolved CO(J=3-2) Star-formation Law

Muraoka, Kazuyuki; Takeda, Miho; Yanagitani, Kazuki; Kaneko, Hiroyuki; Nakanishi, Kouichiro; Kuno, Nario; Sorai, Kazuo; Tosaki, Tomoka; Kohno, Kotaro
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 13/12/2015 Português
Relevância na Pesquisa
46.14748%
We present the results of CO(J=3-2) on-the-fly mappings of two nearby non-barred spiral galaxies NGC 628 and NGC 7793 with the Atacama Submillimeter Telescope Experiment at an effective angular resolution of 25". We successfully obtained global distributions of CO(J=3-2) emission over the entire disks at a sub-kpc resolution for both galaxies. We examined the spatially-resolved (sub-kpc) relationship between CO(J=3-2) luminosities (L'CO(3-2)) and infrared (IR) luminosities (LIR) for NGC 628, NGC 7793, and M 83, and compared it with global luminosities of JCMT Nearby Galaxy Legacy Survey sample. We found a striking linear L'CO(3-2)-LIR correlation over the 4 orders of magnitude, and the correlation is consistent even with that for ultraluminous infrared galaxies and submillimeter selected galaxies. In addition, we examined the spatially-resolved relationship between CO(J=3-2) intensities (ICO(3-2)) and extinction-corrected star formation rates (SFRs) for NGC 628, NGC 7793, and M 83, and compared it with that for GMCs in M 33 and 14 nearby galaxy centers. We found a linear ICO(3-2)-SFR correlation with 1 dex scatter. We conclude that the CO(J=3-2) star formation law (i.e., linear L'CO(3-2)-LIR and ICO(3-2)-SFR correlations) is universally applicable to various types and spatial scales of galaxies...

The James Clerk Maxwell Telescope Nearby Galaxies Legacy Survey IX: $^{12}$CO $J=3\to2$ Observations of NGC 2976 and NGC 3351

Tan, Boon-Kok; Leech, J.; Rigopoulou, D.; Warren, B. E.; Wilson, C. D.; Attewell, D.; Azimlu, M.; Bendo, G. J.; Butner, H. M.; Brinks, E.; Chanial, P.; Clements, D. L.; Heesen, V.; Israel, F.; Knapen, J. H.; Matthews, H. E.; Mortier, A. M. J.; Mühle; Sá
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 28/08/2013 Português
Relevância na Pesquisa
56.125576%
We present $^{12}$CO \textit{J=3$\rightarrow$2} maps of NGC 2976 and NGC 3351 obtained with the James Clerk Maxwell Telescope (JCMT), both early targets of the JCMT Nearby Galaxy Legacy Survey (NGLS). We combine the present observations with $^{12}$CO \textit{J=1$\rightarrow$0} data and find that the computed $^{12}$CO \textit{J=3$\rightarrow$2} to $^{12}$CO \textit{J=1$\rightarrow$0} line ratio ($R_{31}$) agrees with values measured in other NGLS field galaxies. We compute the M$_{\rm{H_2}}$ value and find that it is robust against the value of $R_{31}$ used. Using \textsc{Hi} data from the The \textsc{Hi} Nearby Galaxy Survey (THINGS) survey, we find a tight correlation between surface density of H$_2$ and star formation rate density for NGC 3351 when $^{12}$CO \textit{J=3$\rightarrow$2} data are used. Finally, we compare the $^{12}$CO \textit{J=3$\rightarrow$2} intensity with the PAH 8 $\mu$m surface brightness and find a good correlation in the high surface brightness regions. We extend this study to include all 25 \textit{Spitzer} Infrared Nearby Galaxies Survey (SINGS) galaxies within the NGLS sample and find a tight correlation at large spatial scales. We suggest that both PAH 8 $\mu$m and $^{12}$CO \textit{J=3$\rightarrow$2} are likely to originate in regions of active star formation.; Comment: 15 pages...

Warm and Dense Molecular Gas in the N 159 Region: ^(12)CO J = 4–3 and ^(13)CO J = 3–2 Observations with NANTEN2 and ASTE

Mizuno, Yoji; Kawamura, Akiko; Onishi, Toshikazu; Minamidani, Testuhiro; Muller, Erik; Yamamoto, Hiroaki; Hayakawa, Takahiro; Mizuno, Norikazu; Mizuno, Akira; Stutzki, Jürgen; Pineda, Jorge L.; Klein, Uli; Bertoldi, Frank; Koo, Bon-Chul; Rubio, Monica; B
Fonte: Astronomical Society of Japan Publicador: Astronomical Society of Japan
Tipo: Article; PeerReviewed Formato: application/pdf
Publicado em 25/02/2010 Português
Relevância na Pesquisa
46.20714%
New ^(12)CO J = 4–3 and ^(13)CO J = 3–2 observations of the N 159 region, an active site of massive star formation in the Large Magellanic Cloud, have been made with the NANTEN2 and ASTE submillimeter telescopes, respectively. The ^(12)CO J = 4–3 distribution is separated into three clumps, each associated with N 159 W, N 159 E, and N 159 S. These new measurements toward the three clumps are used in coupled calculations of molecular rotational excitation and line radiation transfer, along with other transitions of the ^(12)CO J = 1–0, J = 2–1, J = 3–2, and J = 7–6 as well as the isotope transitions of ^(13)CO J = 1–0, J = 2–1, J = 3–2, and J = 4–3. The ^(13)CO J = 3–2 data were newly taken for the present work. The temperatures and densities were found to be ~70–80 K and ~3 × 10^3 cm^(-3) in N 159 W and N 159 E, and ~30 K and ~1.6 × 10^3 cm^(-3) in N 159 S. These results were compared with the star-formation activity based on data of young stellar clusters and HII regions as well as midinfrared emission obtained with the Spitzer MIPS. The N 159 E clump is associated with cluster(s) embedded, as observed at 24 μm by the Spitzer MIPS, and the derived high temperature, 80 K, is interpreted as being heated by these sources. The N 159 E clump is likely to be responsible for a dark lane in a large HII region by dust extinction. On the other hand...