47 research outputs found

    Prospective In Vitro

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    An in vitro heart disease model is a promising model used for identifying the genes responsible for the disease, evaluating the effects of drugs, and regenerative medicine. We were interested in disease models using a patient-induced pluripotent stem (iPS) cell-derived cardiomyocytes because of their similarity to a patient's tissues. However, as these studies have just begun, we would like to review the literature in this and other related fields and discuss the path for future models of molecular biology that can help to diagnose and cure diseases, and its involvement in regenerative medicine. The heterogeneity of iPS cells and/or differentiated cardiomyocytes has been recognized as a problem. An in vitro heart disease model should be evaluated using molecular biological analyses, such as mRNA and micro-RNA expression profiles and proteomic analysis

    VLBI Detections of Parsec-Scale Nonthermal Jets in Radio-Loud Broad Absorption Line Quasars

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    We conducted radio detection observations at 8.4 GHz for 22 radio-loud broad absorption line (BAL) quasars, selected from the Sloan Digital Sky Survey (SDSS) Third Data Release, by a very-long-baseline interferometry (VLBI) technique. The VLBI instrument we used was developed by the Optically ConnecTed Array for VLBI Exploration project (OCTAVE), which is operated as a subarray of the Japanese VLBI Network (JVN). We aimed at selecting BAL quasars with nonthermal jets suitable for measuring their orientation angles and ages by subsequent detailed VLBI imaging studies to evaluate two controversial issues of whether BAL quasars are viewed nearly edge-on, and of whether BAL quasars are in a short-lived evolutionary phase of quasar population. We detected 20 out of 22 sources using the OCTAVE baselines, implying brightness temperatures greater than 10^5 K, which presumably come from nonthermal jets. Hence, BAL outflows and nonthermal jets can be generated simultaneously in these central engines. We also found four inverted-spectrum sources, which are interpreted as Doppler-beamed, pole-on-viewed relativistic jet sources or young radio sources: single edge-on geometry cannot describe all BAL quasars. We discuss the implications of the OCTAVE observations for investigations for the orientation and evolutionary stage of BAL quasars.Comment: 10 pages, no figure, 3 tables, accepted for publication in PAS

    Extreme Nature of Four Blue-excess Dust-obscured Galaxies Revealed by Optical Spectroscopy

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    We report optical spectroscopic observations of four blue-excess dust-obscured galaxies (BluDOGs) identified by the Subaru Hyper Suprime-Cam. BluDOGs are a subclass of dust-obscured galaxies (DOGs; defined with the extremely red color (i āˆ’ [22])AB ā‰„ 7.0; Toba et al., showing a significant flux excess in the optical g and r bands over the power-law fits to the fluxes at the longer wavelengths. Noboriguchi et al. have suggested that BluDOGs may correspond to the blowing-out phase involved in a gas-rich major-merger scenario. However, the detailed properties of BluDOGs are not understood because of the lack of spectroscopic information. In this work, we carry out deep optical spectroscopic observations of four BluDOGs using Subaru/FOCAS and VLT/FORS2. The obtained spectra show broad emission lines with extremely large equivalent widths, and a blue wing in the C iv line profile. The redshifts are between 2.2 and 3.3. The averaged rest-frame equivalent widths of the C iv lines are 160 \ub1 33 \uc5, āˆ¼7 times higher than the average of a typical type 1 quasar. The FWHMs of their velocity profiles are between 1990 and 4470 km sāˆ’1, and their asymmetric parameters are 0.05 and 0.25. Such strong C iv lines significantly affect the broadband magnitudes, which are partly the origin of the blue excess seen in the spectral energy distribution of BluDOGs. Their estimated supermassive black hole masses are 1.1 7 108 < M BH/M āŠ™ <5.5 7 108. The inferred Eddington ratios of the BluDOGs are higher than 1 (1.1 < Ī» Edd < 3.8), suggesting that the BluDOGs are in a rapidly evolving phase of supermassive black holes

    Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs). IX. Identification of Two Red Quasars at z > 5.6

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    We present the first discovery of dust-reddened quasars (red quasars) in the high-z universe (z >5.6). This is a result from the Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs) project, which is based on the sensitive multi-band optical imaging data produced by the Hyper Suprime-Cam (HSC) Subaru Strategic Program survey. We identified four red quasar candidates from the spectroscopically confirmed 93 high-z quasars in the SHELLQs sample, based on detections in the Wide-field Infrared Survey Explorer (WISE) data at 3.4 and 4.6 um (rest-frame ~5000-6500 A). The amount of dust reddening was estimated with spectral energy distribution (SED) fits over optical and mid-infrared wavelengths. Two of the four candidates were found to be red quasars with dust reddening of E(B-V) > 0.1. The remaining SHELLQs quasars without individual WISE detections are significantly fainter in the WISE bands and bluer than the red quasars, although we did detect them in the W1 band in a stacked image. We also conducted the same SED fits for high-z optically-luminous quasars, but no red quasar was found. This demonstrates the power of Subaru HSC to discover high-z red quasars, which are fainter than the limiting magnitudes of past surveys in the rest-frame ultraviolet, due to dust extinction.Comment: Accepted for publication in PAS

    Discovery of the First Low-Luminosity Quasar at z > 7

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    We report the discovery of a quasar at z = 7.07, which was selected from the deep multi-band imaging data collected by the Hyper Suprime-Cam (HSC) Subaru Strategic Program survey. This quasar, HSC J124353.93+010038.5, has an order of magnitude lower luminosity than do the other known quasars at z > 7. The rest-frame ultraviolet absolute magnitude is M1450 = -24.13 +/- 0.08 mag and the bolometric luminosity is Lbol = (1.4 +/- 0.1) x 10^{46} erg/s. Its spectrum in the optical to near-infrared shows strong emission lines, and shows evidence for a fast gas outflow, as the C IV line is blueshifted and there is indication of broad absorption lines. The Mg II-based black hole mass is Mbh = (3.3 +/- 2.0) x 10^8 Msun, thus indicating a moderate mass accretion rate with an Eddington ratio 0.34 +/- 0.20. It is the first z > 7 quasar with sub-Eddington accretion, besides being the third most distant quasar, known to date. The luminosity and black hole mass are comparable to, or even lower than, those measured for the majority of low-z quasars discovered by the Sloan Digital Sky Survey, and thus this quasar likely represents a z > 7 counterpart to quasars commonly observed in the low-z universe.Comment: Accepted for publication in ApJ Letter

    Subaru High-z Exploration of Low-luminosity Quasars (SHELLQs). X. Discovery of 35 Quasars and Luminous Galaxies at 5.7 ā‰¤ z ā‰¤ 7.0

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    The American Astronomical Society, find out more The Institute of Physics, find out more THE FOLLOWING ARTICLE ISOPEN ACCESS Subaru High-z Exploration of Low-luminosity Quasars (SHELLQs). X. Discovery of 35 Quasars and Luminous Galaxies at 5.7 ā‰¤ z ā‰¤ 7.0 Yoshiki Matsuoka1, Kazushi Iwasawa2, Masafusa Onoue3, Nobunari Kashikawa4,5,6, Michael A. Strauss7, Chien-Hsiu Lee8, Masatoshi Imanishi5,6, Tohru Nagao1, Masayuki Akiyama9, Naoko Asami10Show full author list Published 2019 October 3 Ā© 2019. The American Astronomical Society. The Astrophysical Journal, Volume 883, Number 2 DownloadArticle PDF DownloadArticle ePub Figures Tables References Download PDFDownload ePub 674 Total downloads 99 total citations on Dimensions. Turn on MathJax Share this article Share this content via email Share on Facebook Share on Twitter Share on Google+ Share on Mendeley Article information Abstract We report the discovery of 28 quasars and 7 luminous galaxies at 5.7 ā‰¤ z ā‰¤ 7.0. This is the tenth in a series of papers from the Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs) project, which exploits the deep multiband imaging data produced by the Hyper Suprime-Cam (HSC) Subaru Strategic Program survey. The total number of spectroscopically identified objects in SHELLQs has now grown to 93 high-z quasars, 31 high-z luminous galaxies, 16 [O iii] emitters at z ~ 0.8, and 65 Galactic cool dwarfs (low-mass stars and brown dwarfs). These objects were found over 900 deg2, surveyed by HSC between 2014 March and 2018 January. The full quasar sample includes 18 objects with very strong and narrow LyĪ± emission, whose stacked spectrum is clearly different from that of other quasars or galaxies. While the stacked spectrum shows N v Ī»1240 emission and resembles that of lower-z narrow-line quasars, the small LyĪ± width may suggest a significant contribution from the host galaxies. Thus, these objects may be composites of quasars and star-forming galaxies

    Discovery of the First Low-luminosity Quasar at z > 7

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    We report the discovery of a quasar at z = 7.07, which was selected from the deep multi-band imaging data collected by the Hyper Suprime-Cam (HSC) Subaru Strategic Program survey. This quasar, HSC J124353.93+010038.5, has an order of magnitude lower luminosity than do the other known quasars at z > 7. The rest-frame ultraviolet absolute magnitude is M1450 = āˆ’24.13 Ā± 0.08 mag and the bolometric luminosity is Lbolā€‰=(1.4Ā±0.1)ā€‰Ć—ā€‰1046{L}_{\mathrm{bol}}\,=(1.4\pm 0.1)\,\times \,{10}^{46} erg sāˆ’1. Its spectrum in the optical to near-infrared shows strong emission lines, and shows evidence for a fast gas outflow, as the C iv line is blueshifted and there is indication of broad absorption lines. The Mg ii-based black hole mass is MBH=(3.3Ā±2.0)Ɨ108MāŠ™{M}_{\mathrm{BH}}=(3.3\pm 2.0)\times {10}^{8}{M}_{\odot }, thus indicating a moderate mass accretion rate with an Eddington ratio Ī»Edd=0.34Ā±0.20{\lambda }_{\mathrm{Edd}}=0.34\pm 0.20. It is the first z > 7 quasar with sub-Eddington accretion, besides being the third most distant quasar known to date. The luminosity and black hole mass are comparable to, or even lower than, those measured for the majority of low-z quasars discovered by the Sloan Digital Sky Survey, and thus this quasar likely represents a z > 7 counterpart to quasars commonly observed in the low-z universe

    Subaru High- z Exploration of Low-luminosity Quasars (SHELLQs). XVI. 69 New Quasars at 5.8 < z < 7.0

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    We present the spectroscopic discovery of 69 quasars at 5.8 0.1 in the HSC-SSP third public data release (PDR3). The sample reported here also includes three quasars with PQB 5.6. This demonstrates that the algorithm has very high efficiency, even though we are probing an unprecedentedly low luminosity population down to M 1450 āˆ¼-21 mag.Y.M. was supported by the Japan Society for the Promotion of Science (JSPS) KAKENHI grant No. JP17H04830, No. 21H04494, and the Mitsubishi Foundation grant No. 30140. K.I. acknowledges support by the Spanish MCIN under grant PID2019-105510GB-C33/AEI/10.13039/501100011033 and "Unit of excellence MarĆ­a de Maeztu 2020-2023" awarded to ICCUB (CEX2019-000918-M)
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