119 research outputs found
The ALMA Discovery of the Rotating Disk and Fast Outflow of Cold Molecular Gas in NGC 1275
We present ALMA Band 6 observations of the CO(2-1), HCN(3-2), and
HCO(3-2) lines in the nearby radio galaxy / brightest cluster galaxy
(BCG) of NGC 1275 with the spatial resolution of pc. In the previous
observations, CO(2-1) emission was detected as radial filaments lying in the
east-west direction. We resolved the inner filament and found that the filament
cannot be represented by a simple infalling stream both morphologically and
kinematically. The observed complex nature of the filament resembles the cold
gas structure predicted by recent numerical simulations of cold chaotic
accretion. A crude estimate suggests that the accretion rate of the cold gas
can be higher than that of hot gas. Within the central 100 pc, we detected a
rotational disk of the molecular gas whose mass is \sim10^{8} M_{\sun}. This
is the first evidence of the presence of massive cold gas disk on this spatial
scale for BCGs. The disk rotation axis is approximately consistent with the
axis of the radio jet on subpc scales. This probably suggests that the cold gas
disk is physically connected to the innermost accretion disk which is
responsible for jet launching. We also detected absorption features in the
HCN(3-2) and HCO(3-2) spectra against the radio continuum emission mostly
radiated by -pc size jet. The absorption features are blue-shifted
from the systemic velocity by 300-600~km~s, which suggests the
presence of outflowing gas from the active galactic nucleus (AGN). We discuss
the relation of the AGN feeding with cold accretion, the origin of blue-shifted
absorption, and estimate of black hole mass using the molecular gas dynamics.Comment: Version 2 (accepted version). 18 pages, 16 figures. Accepted for
publication in Ap
Suzaku Observation of Abell 1689: Anisotropic Temperature and Entropy Distributions Associated with the Large-Scale Structure
(Abridged) We present results of Suzaku observations of the intracluster
medium (ICM) in Abell 1689, combined with complementary analysis of the SDSS
data and weak and strong lensing analysis of Subaru/Suprime-Cam and HST/ACS
observations. Faint X-ray emission from the ICM around the virial radius is
detected at 4.0 sigma significance. We find anisotropic gas temperature and
entropy distributions in cluster outskirts correlated with large-scale
structure of galaxies. The high temperature and entropy region in the
northeastern (NE) outskirts is connected to an overdense filamentary structure.
The outskirt regions in contact with low density void environments have low gas
temperatures and entropies, deviating from hydrostatic equilibrium. These
results suggest that thermalization of the ICM occurs faster along the
filamentary structures than the void regions. A joint X-ray and lensing
analysis shows that the hydrostatic mass is of spherical lensing
one but comparable to a triaxial halo mass within errors in 0.6r_{2500} \simlt
r \simlt 0.8r_{500}, and that it is significantly biased as low as \simlt60%
within , irrespective of mass models. The thermal gas pressure
within is, at most, --60% of the total pressure to balance
fully the gravity of the spherical lensing mass, and --40% around the
virial radius. Although these constitute lower limits when one considers the
possible halo triaxiality, these small relative contributions of thermal
pressure would require additional sources of pressure, such as bulk and/or
turbulent motions.Comment: 24 pages, 15 figures, 9 tables. Accepted for publication in Ap
Alternative Starting Position for CT Coronary Angiography
We examined whether the superior margin of the left main bronchus is the best landmark for the starting position of computed tomography coronary angiography(CTCA). We retrospectively evaluated 693 consecutive CTCAs. From the scout scanogram, the superior margin of the left main bronchus was noted. The relationships among and distance between the superior margin of the left main bronchus and the left coronary system were analyzed. The superior margin of the left main bronchus extended caudally to the superior margin of the left coronary system in 13 patients(1.9%). The addition of 1cm to the superior margin of the left main bronchus kept it caudal to the superior margin of the left coronary system in only one patient(0.1%). On the scout scanogram, 1cm above the superior margin of the left main bronchus is the most appropriate starting position for CTCA
Purified Mesenchymal Stem Cells Are an Efficient Source for iPS Cell Induction
Induced pluripotent stem (iPS) cells are generated from mouse and human somatic cells by the forced expression of defined transcription factors. Although most somatic cells are capable of acquiring pluripotency with minimal gene transduction, the poor efficiency of cell reprogramming and the uneven quality of iPS cells are still important problems. In particular, the choice of cell type most suitable for inducing high-quality iPS cells remains unclear.Here, we generated iPS cells from PDGFRα+ Sca-1+ (PαS) adult mouse mesenchymal stem cells (MSCs) and PDGFRα⁻ Sca-1⁻ osteo-progenitors (OP cells), and compared the induction efficiency and quality of individual iPS clones. MSCs had a higher reprogramming efficiency compared with OP cells and Tail Tip Fibroblasts (TTFs). The iPS cells induced from MSCs by Oct3/4, Sox2, and Klf4 appeared to be the closest equivalent to ES cells by DNA microarray gene profile and germline-transmission efficiency.Our findings suggest that a purified source of undifferentiated cells from adult tissue can produce high-quality iPS cells. In this context, prospectively enriched MSCs are a promising candidate for the efficient generation of high-quality iPS cells
Analysis of DNA double-strand break response and chromatin structure in mitosis using laser microirradiation
In this study the femtosecond near-IR and nanosecond green lasers are used to induce alterations in mitotic chromosomes. The subsequent double-strand break responses are studied. We show that both lasers are capable of creating comparable chromosomal alterations and that a phase paling observed within 1–2 s of laser exposure is associated with an alteration of chromatin as confirmed by serial section electron microscopy, DAPI, γH2AX and phospho-H3 staining. Additionally, the accumulation of dark material observed using phase contrast light microscopy (indicative of a change in refractive index of the chromatin) ∼34 s post-laser exposure corresponds spatially to the accumulation of Nbs1, Ku and ubiquitin. This study demonstrates that chromosomes selectively altered in mitosis initiate the DNA damage response within 30 s and that the accumulation of proteins are visually represented by phase-dark material at the irradiation site, allowing us to determine the fate of the damage as cells enter G1. These results occur with two widely different laser systems, making this approach to study DNA damage responses in the mitotic phase generally available to many different labs. Additionally, we present a summary of most of the published laser studies on chromosomes in order to provide a general guide of the lasers and operating parameters used by other laboratories
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