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Discovery of 16 New z ∼ 5.5 Quasars: Filling In The Redshift Gap of Quasar Color Selection

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arXiv 2017年

作者： Yang, Jinyi Fan, Xiaohui Wu, Xue-Bing Wang, Feige Bian, Fuyan Yang, Qian McGreer, Ian D. Yi, Weimin Jiang, Linhua Green, Richard Yue, Minghao Wang, Shu Li, Zefeng Ding, Jiani Dye, Simon Lawrence, Andy Department of Astronomy School of Physics Peking University Beijing100871 China Kavli Institute for Astronomy and Astrophysics Peking University Beijing100871 China Steward Observatory University of Arizona 933 North Cherry Avenue TucsonAZ85721 United States Research School of Astronomy and Astrophysics Australian National University Weston CreekACT2611 Australia Yunnan Observatories Chinese Academy of Sciences Kunming650011 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming650011 China School of Physics and Astronomy Nottingham University University Park NottinghamNG7 2RD United Kingdom Institute for Astronomy University of Edinburgh Royal Observatory Blackford Hill EdinburghEH9 3HJ United Kingdom

We present initial results from the first systematic survey of luminous z ∼ 5.5 quasars. Quasars at z ∼ 5.5, the post-reionization epoch, are crucial tools to explore the evolution of intergalactic medium, quasar evolution and the early super-massive black hole growth. However, it has been very challenging to select quasars at redshifts 5.3 ≤ z ≤ 5.7 using conventional color selections, due to their similar optical colors to late-type stars, especially M dwarfs, resulting in a glaring redshift gap in quasar redshift distributions. We develop a new selection technique for z ∼ 5.5 quasars based on optical, near-IR and mid-IR photometric data from Sloan Digital Sky Survey (SDSS), UKIRT InfraRed Deep Sky Surveys - Large Area Survey (ULAS), VISTA Hemisphere Survey (VHS) and Wide field Infrared Survey Explorer (WISE). From our pilot observations in SDSS-ULAS/VHS area, we have discovered 15 new quasars at 5.3 ≤ z ≤ 5.7 and 6 new lower redshift quasars, with SDSS z band magnitude brighter than 20.5. Including other two z ∼ 5.5 quasars already published in our previous work, we now construct an uniform quasar sample at 5.3 ≤ z ≤ 5.7 with 17 quasars in a ∼ 4800 square degree survey area. For further application in a larger survey area, we apply our selection pipeline to do a test selection by using the new wide field J band photometric data from a preliminary version of the UKIRT Hemisphere Survey (UHS). We successfully discover the first UHS selected z ∼ 5.5 quasar. Subject headings: galaxies: active - galaxies:high-redshift - quasars: general - quasars: emission lines Copyright © 2017, The Authors. All rights reserved.

关键词： Galaxies

Warm molecular hydrogen in nearby, luminous infrared galaxies

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arXiv 2018年

作者： Petric, Andreea O. Armus, Lee Flagey, Nicolas Guillard, Pierre Howell, Justin Inami, Hanae Charmandaris, Vassillis Evans, Aaron Stierwalt, Sabrina Diaz-Santos, Tanio Lu, Nanyao Spoon, Henrik Mazzarella, Joe Appleton, Phil Chan, Ben Chu, Jason Hand, Derek Privon, George Sanders, David Surace, Jason Xu, Kevin Zhao, Yinghe Institute for Astronomy 2680 Woodlawn Drive HonoluluHI96822 United States Canada-France-Hawaii Telescope 65-1238 Mamalahoa Highway KamuelaHI96743 United States Infrared Processing & Analysis Center California Institute of Technology MS 100-22 PasadenaCA91125 United States Institut d'Astrophysique de Paris 96 bis boulevard Arago Paris75014 France Universite de Lyon 92 Rue Pasteur Lyon69007 France Department of Physics University of Crete HeraklionGR-71003 Greece IAASARS National Observatory of Athens PenteliGR-15236 Greece Department of Astronomy University of Virginia CharlottesvilleVA22903 United States National Radio Astronomy Observatory 520 Edgemont Road CharlottesvilleVA22903 United States Nucleo de Astronomia de la Facultad de Ingenieria Universitad Diego Portales Av. Ejercito Libertador 441 Santiago Chile Beijing100012 China China-Chile Joint Center for Astronomy Camino El Observatorio 1515 Las Condes Santiago Chile Department of Astronomy Cornell University 616A Space Science Building IthacaNY14853 United States Department of Physics and Astronomy University of Hawaii 200 W. Kawili St. HiloHI96720 United States Instituto de Astrofisica Facultad de Fisica Pontificia Universitad Catolica de Chile Casilla 306 Santiago22 Chile Yunnan Observatories CAS Kumming65011 China Key Laboratory for the Structure and Evolution of Celestial Objects CAS Kumming65011 China Purple Mountain Observatory CAS Nanjing210008 China

Mid-infrared molecular hydrogen (H2) emission is a powerful cooling agent in galaxy mergers and in radio galaxies;it is a potential key tracer of gas evolution and energy dissipation associated with mergers, star formation, and accretion onto supermassive black holes. We detect mid-IR H2line emission in at least one rotational transition in 91% of the 214 Luminous Infrared Galaxies (LIRGs) observed with Spitzer as part of the Great Observatories All-sky LIRG Survey (GOALS). We use H2excitation diagrams to estimate the range of masses and temperatures of warm molecular gas in these galaxies. We find that LIRGs in which the IR emission originates mostly from the Active Galactic Nuclei (AGN) have about 100K higher H2mass-averaged excitation temperatures than LIRGs in which the IR emission originates mostly from star formation. Between 10 and 15% of LIRGs have H2emission lines that are sufficiently broad to be resolved or partially resolved by the high resolution modules of Spitzer's Infrared Spectrograph (IRS). Those sources tend to be mergers and contain AGN. This suggests that a significant fraction of the H2line emission is powered by AGN activity through X-rays, cosmic rays, and turbulence. We find a statistically significant correlation between the kinetic energy in the H2gas and the H2to IR luminosity ratio. The sources with the largest warm gas kinetic energies are mergers. We speculate that mergers increase the production of bulk in-flows leading to observable broad H2profiles and possibly denser environments. Copyright © 2018, The Authors. All rights reserved.

关键词： Galaxies

The THU-NAOC transient survey: the performance and results from the first year

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Research in Astronomy and Astrophysics 2015年第2期15卷 215-224页

作者： Tian-Meng Zhang Xiao-Feng Wang Jun-Cheng Chen Ju-Jia Zhang Li Zhou Wen-Xiong Li Qing Liu Jun Mo Kai-Cheng Zhang Xin-Yu Yao Xu-Lin Zhao Xu Zhou Jun-Dan Nie Fang Huang Zhao-Ji Jiang Jun Ma Ling-Zhi Wang Chao Wu Zhi-Min Zhou Hu Zou Li-Fan Wang Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Physics Department and Tsinghua Center for Astrophysics Tsinghua University Yunnan Observatories Chinese Academy of Sciences Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences University of Chinese Academy of Sciences Purple Mountain Observatory Chinese Academy of Sciences Astronomy Department Beijing Normal University National Astronomical Observatories Chinese Academy of Sciences

The Tsinghua University-National Astronomical Observatories, Chinese Academy of Sciences （NAOC） Transient Survey is an automatic survey that conducts a systematic exploration of optical transients. This project utilizes a 60/90 cm Schmidt telescope at the Xinglong Station of NAOC. This survey repeatedly covers - 1000 square degrees of the northern sky with a cadence of 34 d. With an exposure of 60 s, the survey reaches a limiting unfiltered magnitude of about 19.5 mag, which enables us to discover supernovae in their relatively young stages. We describe the overall performance of our survey during the first year and present some preliminary results.

关键词： supernovae quasars and active galactic nuclei stars

The nearby evolved stars survey: I. JCMT/SCUBA-2 Sub-millimetre detection of the detached shell of U Antliae

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arXiv 2019年

作者： Dharmawardena, Thavisha E. Kemper, Francisca Srinivasan, Sundar Scicluna, Peter Marshall, Jonathan P. Wouterloot, Jan G.A. Greaves, Jane Goldman, Steven R. van Loon, Jacco Th. Matsuura, Mikako McDonald, Iain He, Jinhua Zijlstra, Albert A. Toalá, Jesús A. Wallström, Sofia H.J. Kim, Hyosun Trejo, Alfonso Ventura, Paolo Lagadec, Eric Boyer, Martha L. Liu, Tie Rau, Gioia Izumiura, Hideyuki Cami, Jan Holland, Wayne Jones, Olivia Shinnaga, Hiroko Academia Sinica Institute of Astronomy and Astrophysics 11F of AS/NTU Astronomy-Mathematics Building No.1 Sec. 4 Roosevelt Rd Taipei10617 Taiwan Graduate Institute of Astronomy National Central University 300 Zhongda Road Zhongli Taoyuan32001 Taiwan European Southern Observatory Karl-Schwarzschild-Str. 2 Garching b. München85748 Germany Instituto de Radioastronomía y Astrofísica Universidad Nacional Autónoma de México Antigua Carretera a Pátzcuaro # 8701 Ex-Hda. San José de la Huerta MoreliaMichoacánC.P. 58089 Mexico East Asian Observatory 660 N A’ohoku Place HiloHI96720 United States School of Physics and Astronomy Cardiff University 4 The Parade CardiffCF24 3AA United Kingdom STScI 3700 San Martin Drive BaltimoreMD21218 United States Lennard-Jones Laboratories Keele University ST5 5BG United Kingdom Jodrell Bank Centre for Astrophysics Alan Turing Building University of Manchester ManchesterM13 9PL United Kingdom Key Laboratory for the Structure and Evolution of Celestial Objects Yunnan Observatories Chinese Academy of Sciences 396 Yangfangwang Guandu District Kunming650216 China Chinese Academy of Sciences South America Center for Astronomy China-Chile Joint Center for Astronomy Camino El Observatorio #1515 Las Condes Santiago Chile Departamento de Astronomía Universidad de Chile Casilla 36-D Santiago Chile Laboratory for Space Research University of Hong Kong Pokfulam Road Hong Kong Institute of Astronomy KU Leuven Celestijnenlaan 200D bus 2401 Leuven3001 Belgium Korea Astronomy and Space Science Institute 776 Daedukdae-ro Yuseong-gu Daejeon34055 Korea Republic of INAF Osservatorio Astronomico di Roma Via Frascati 33 Monte Porzio Catone Roma00077 Italy Université Côte d’Azur Observatoire de la Côte d’Azur CNRS Lagrange France NASA/GSFC Code 667 Goddard Space Flight Center GreenbeltMD20071 United States CRESST II Department of Physics Catholic University of America WashingtonDC20064 United States Okayama Branch

We present the highest resolution single-dish submillimetre observations of the detached shell source U Antliae to date. The observations were obtained at 450 µm and 850 µm with SCUBA-2 instrument on the James Clerk Maxwell Telescope as part of the Nearby Evolved Stars Survey. The emission at 850 µm peaks at 4000 with hints of a second peak seen at ∼ 2000. The emission can be traced out to a radius of 5600 at a 3σ level. The outer peak observed at 850 µm aligns well with the peak observed at Herschel/PACS wavelengths. With the help of spectral energy distribution fitting and radiative transfer calculations of multiple-shell models for the circumstellar envelope, we explore the various shell structures and the variation of grain sizes along the in the circumstellar envelope. We determine a total shell dust mass of (2.0±0.3)×10−5 M☉ and established that the thermal pulse which gave rise to the detached shell occurred 3500 ± 500 years ago. Copyright © 2019, The Authors. All rights reserved.

关键词： Shells (structures)

Long-term transit timing monitoring and homogenous study of WASP-32

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Research in Astronomy and Astrophysics 2015年第1期15卷 117-126页

作者： Lei-Lei Sun Sheng-Hong Gu Xiao-Bin Wang Andrew Collier Cameron Dong-Tao Cao Yi-Bo Wang Yue Xiang Ho-Keung Hui Chi-Tai Kwok Bill Yeung Kam-Cheung Leung Yunnan Observatories Chinese Academy of Sciences Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences University of Chinese Academy of Sciences School of Physics and Astronomy University of St Andrews North Haugh St Andrews Fife KY16 9SS UK Ho Koon Nature Education cum Astronomical Centre Hong Kong Astronomical Society

We report new photometric observations of the transiting exoplanetary system WASP-32 made by using CCD cameras at Yunnan Observatories and Ho Koon Nature Education cum Astronomical Centre, China from 2010 to 2012. Following our usual procedure, the observed data are corrected for systematic errors according to the coarse decorrelation and SYSREM algorithms so as to enhance the signal of the transit events. Combined with radial velocity data presented in the literature, our newly observed data and earlier photometric data in the literature are simultaneously analyzed to derive the physical parameters describing the system by employing the Markov chain Monte Carlo technique. The derived parameters are consistent with the result published in the original paper about WASP-32b, but the uncertainties of the new parameters are smaller than those in the original paper. Moreover, our modeling result supports a circular orbit for WASP-32b. Through the analysis of all available mid-transit times, we have refined the orbital period of WASP-32b; no evident transit timing variation is found in these transit events.

关键词： techniques： photometric transiting exoplanetary system individual： WASP-32

Galactic continuum surveys with the new 850 µm MKID camera at the EAO/JCMT 15-M telescope

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arXiv 2019年

作者： Liu, Tie Li, Di Eden, David Di Francesco, James He, JinHua Sadavoy, Sarah I. Tatematsu, Ken'ichi Kim, Kee-Tae Hirano, Naomi Fuller, Gary Wu, Yuefang Liu, Sheng-Yuan Wang, Ke Thompson, Mark Juvela, Mika Ristorcelli, Isabelle Viktor Toth, L. Soam, Archana Sanhueza, Patricio Kang, Sung-Ju Kwon, Woojin Ward-Thompson, D. Montillaud, Julien Richer, John Xie, Jinjin Wang, Bingru Zhang, Yapeng East Asian Observatory 660 N. A'ohoku Place HiloHI96720 United States National Astronomical Observatories Chinese Academy of Science A20 Datun Road Chaoyang District Beijing100012 China Key Laboratory for Radio Astronomy Chinese Academy of Sciences Nanjing210008 China Astrophysics Research Institute Liverpool John Moores University IC2 Liverpool Science Park 146 Brownlow Hill LiverpoolL3 5RF United Kingdom NRC Herzberg Astronomy and Astrophysics 5071 West Saanich Rd. VictoriaBCV9E 2E7 Canada Department of Physics and Astronomy University of Victoria VictoriaBCV8P 1A1 Canada Key Laboratory for the Structure and Evolution of Celestial Objects Yunnan Observatories Chinese Academy of Sciences P.O. Box 110 Kunming Yunnan Province650011 China Camino El Observatorio 1515 Las Condes Santiago Chile Departamento de Astronomía Universidad de Chile Las Condes Santiago Chile Harvard-Smithsonian Center for Astrophysics 60 Garden Street CambridgeMA02138 United States National Astronomical Observatory of Japan 2-21-1 Osawa Mitaka Tokyo181-8588 Japan Korea Astronomy and Space Science Institute 776 Daedeokdae-ro Yuseong-gu Daejeon34055 Korea Republic of Institute of Astronomy and Astrophysics Academia Sinica. 11F of Astronomy-Mathematics Building AS/NTU No.1 Sec. 4 Roosevelt Rd Taipei10617 Taiwan UK ALMA Regional Centre Node Jodrell Bank Centre for Astrophysics School of Physics and Astronomy University of Manchester Oxford Road ManchesterM13 9PL United Kingdom Department of Astronomy Peking University Beijing100871 China Academia Sinica Institute of Astronomy and Astrophysics P.O. Box 23-141 Taipei106 Taiwan Kavli Institute for Astronomy and Astrophysics Peking University Beijing100871 China Centre for Astrophysics Research School of Physics Astronomy & Mathematics University of Hertfordshire College Lane HatfieldAL10 9AB United Kingdom Department of Physics University of Helsinki P.O.Box 64 FI-00014 Finland IRAP Université de

This white paper gives a brief summary of Galactic continuum surveys with the next generation 850 µm camera at the James Clerk Maxwell Telescope (JCMT) in the next decade. This new camera will have mapping speeds at least 10-20 times faster than the present SCUBA-2 camera, and will enable deep (−1) and extensive continuum surveys such as a wider (−5◦ ◦, |b| ◦) Galactic Plane survey, a larger Gould Belt survey, and a follow-up survey of all Planck compact objects visible from the northern hemisphere. These surveys will provide a complete census of molecular clouds, filaments, and dense cores across the Galaxy, vital for studying star formation in various environments. Copyright © 2019, The Authors. All rights reserved.

关键词： Surveys

A ringed dwarf liner 1 galaxy hosting an intermediate-mass black hole with large-scale rotation-like Hα emission

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arXiv 2017年

作者： Liu, Wen-Juan Qian, Lei Dong, Xiao-Bo Jiang, Ning Lira, Paulina Cai, Zheng Wang, Feige Yang, Jinyi Xiao, Ting Kim, Minjin Yunnan Observatories Chinese Academy of Sciences Kunming Yunnan650011 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming Yunnan650011 China Center for Astronomical Mega-Science Chinese Academy of Sciences 20A Datun Road Chaoyang District Beijing100012 China National Astronomical Observatories Chinese Academy of Sciences Beijing100012 China Department of Astronomy University of Science and Technology of China Hefei Anhui230026 China Departamento de Astronomía Universidad de Chile Casilla 36-D Santiago Chile UCO Lick Observatory University of California 1156 High Street Santa CruzCA95064 United States Department of Astronomy School of Physics Peking University Beijing100871 China Key Laboratory for Research in Galaxies and Cosmology Shanghai Astronomical Observatory Chinese Academy of Sciences 80 Nandan Rd Shanghai200030 China Korea Astronomy and Space Science Institute Daejeon305-348 Korea Republic of University of Science and Technology Daejeon305-350 Korea Republic of

We report the discovery of a 20-kpc-sized Hα emission in SDSS J083803.68+540642.0, a ringed dwarf galaxy (MV = 17.89 mag) hosting an accreting intermediate-mass black hole at z = 0.02957. Analysis of the HST images indicates that it is an early-type galaxy with a featureless low-surface brightness disk (µ0 = 20.39 mag arcsec 2 in the V band) and a prominent, relatively red bulge (V I = 2.03, Re = 0.28 kpc or 0.′′48) that accounts for ≈81% of the total light in the I band. A circumgalactic ring of a diameter 16 kpc is also detected, with a disperse shape on its south side. The optical emission lines reveal the nucleus to be a broad-line LINER. Our MMT longslit observation indicates that the kinematics of the extended Hα emission is consistent with a rotational gaseous disk, with a mean blueshifted velocity of 162 km s 1 and mean redshifted velocity of 86 km s 1. According to our photoionization calculations, the large-scale Hα emission is unlikely to be powered by the central nucleus or by hot evolved (post-AGB) stars interspersed in the old stellar populations, but by in situ star formation;this is vindicated by the line-ratio diagnostic of the extended emission. We propose that both the ring and large-scale Hα-emitting gas are created by the tidal accretion in a collision-and then merger-with a gas-rich galaxy of a comparable mass. Copyright © 2017, The Authors. All rights reserved.

关键词： Galaxies

The first symbiotic stars from the LAMOST survey

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Research in Astronomy and Astrophysics 2015年第8期15卷 1332-1341页

作者： Jiao Li Joanna Mikolajewska Xue-Fei Chen A-Li Luo Alberto Rebassa-Mansergas Yong-Hui Hou Yue-Fei Wang Yue Wu Ming Yang Yong Zhang Zhan-Wen Han Key Laboratory for the Structure and Evolution of Celestial Objects Yunnan ObservatoriesChinese Academy of Sciences University of Chinese Academy of Sciences Nicolaus Copernicus Astronomical Centre Bartycka 1800716 WarsawPoland National Astronomical Observatories Chinese Academy of Sciences Kavli Institute for Astronomy and Astrophysics Peking University Nanjing Institute of Astronomical Optics & Technology National Astronomical ObservatoriesChinese Academy of Sciences

Symbiotic stars are interacting binary systems with the longest orbital periods. They are typically formed by a white dwarf and a red giant that are embedded in a nebula. These objects are natural astrophysical laboratories for studying the evolution of binaries. Current estimates of the population of symbiotic stars in the Milky Way vary from 3000 up to 400 000. However, a current census has found less than 300. The Large sky Area Multi-Object fiber Spectroscopic Telescope（LAMOST） survey can obtain hundreds of thousands of stellar spectra per year, providing a good opportunity to search for new symbiotic stars. We detect four such binaries among 4 147 802 spectra released by LAMOST, of which two are new identifications. The first is LAMOST J12280490–014825.7, considered to be an S-type halo symbiotic star. The second is LAMOST J202629.80＋423652.0, a D-type symbiotic star.

关键词： binaries： symbiotic-stars—optical spectra—LAMOST

DISCOVERY of A REDBACK MILLISECOND PULSAR CANDIDATE: 3FGL J0212.1+5320

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Astrophysical Journal 2016年第2期833卷

作者： Li, Kwan-Lok Kong, Albert K. H. Hou, Xian Mao, Jirong Strader, Jay Chomiuk, Laura Tremou, Evangelia Department of Physics and Astronomy Michigan State University East Lansing 48824 MI United States Institute of Astronomy Department of Physics National Tsing Hua University Hsinchu 30013 Taiwan Yunnan Observatories Chinese Academy of Sciences Kunming 650216 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming 650216 China

We present a multiwavelength study of the unidentified Fermi object, 3FGL J0212.1+5320. Within the 95% error ellipse, Chandra detects a bright X-ray source (i.e., F0.5-7keV = 1.4 × 10-12erg cm-2 s-1) that has a l... 详细信息

We present a multiwavelength study of the unidentified Fermi object, 3FGL J0212.1+5320. Within the 95% error ellipse, Chandra detects a bright X-ray source (i.e., F_0.5-7keV = 1.4 × 10^-12erg cm^-2 s^-1) that has a low-mass optical counterpart (M ≲ 0.4 M_⊙ and T ∼ 6000 K). A clear ellipsoidal modulation is shown in optical/infrared at 20.87 hr. The gamma-ray properties of 3FGL J0212.1+5320 are all consistent with that of a millisecond pulsar (MSP), suggesting that it is a γ-ray redback (RB) MSP binary with a low-mass companion filling 64% of the Roche lobe. If confirmed, it will be an RB binary with one of the longest orbital periods known. Spectroscopic data taken in 2015 from the Lijiang observatory show no evidence of strong emission lines, revealing that the accretion is currently inactive (the rotation-powered pulsar state). This is consistent with the low X-ray luminosities (L_x ≈ 10³² erg s^-1) and the possible X-ray modulation seen by Chandra and Swift. Considering that the X-ray luminosity and the high X-ray-to-γ-ray flux ratio (8%) are both comparable to those of the two known γ-ray transitional MSPs, we suspect that 3FGL J0212.1+5320 could be a potential target to search for future transition to the accretion active state. © 2016. The American Astronomical Society. All rights reserved.

关键词： binaries: close gamma-rays: stars pulsars: general X-rays: binaries