Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
X-ray groups and clusters of galaxies in the Subaru-XMM Deep Field  [PDF]
A. Finoguenov,M. G. Watson,M. Tanaka,C. Simpson,M. Cirasuolo,J. S. Dunlop,J. A. Peacock,D. Farrah,M. Akiyama,Y. Ueda,V. Smolcic,G. Stewart,S. Rawlings,C. van Breukelen,O. Almaini,L. Clewley,D. G. Bonfield,M. J. Jarvis,J. M. Barr,S. Foucaud,R. J. McLure,K. Sekiguchi,E. Egami
Physics , 2009, DOI: 10.1111/j.1365-2966.2010.16256.x
Abstract: We present the results of a search for galaxy clusters in Subaru-XMM Deep Field. We reach a depth for a total cluster flux in the 0.5-2 keV band of 2x10^{-15} ergs cm^{-2} s^{-1} over one of the widest XMM-Newton contiguous raster surveys, covering an area of 1.3 square degrees. Cluster candidates are identified through a wavelet detection of extended X-ray emission. The red sequence technique allows us to identify 57 cluster candidates. We report on the progress with the cluster spectroscopic follow-up and derive their properties based on the X-ray luminosity and cluster scaling relations. In addition, 3 sources are identified as X-ray counterparts of radio lobes, and in 3 further sources, X-ray counterpart of radio lobes provides a significant fraction of the total flux of the source. In the area covered by NIR data, our identification success rate achieves 86%. We detect a number of radio galaxies within our groups and for a luminosity-limited sample of radio galaxies we compute halo occupation statistics using a marked cluster mass function. We compare the cluster detection statistics in the SXDF with the predictions of concordance cosmology and current knowledge of the X-ray cluster properties, concluding that a reduction of concordance sigma_8 value by 5% is required in order to match the prediction of the model and the data. This conclusion still needs verification through the completion of cluster follow-up.
The Mass-Dependent Clustering History of K-selected Galaxies at z < 4 in the SXDS/UDS Field  [PDF]
Junko Furusawa,Kazuhiro Sekiguchi,Tadafumi Takata,Hisanori Furusawa,Kazuhiro Shimasaku,Chris Simpson,Masayuki Akiyama
Physics , 2011, DOI: 10.1088/0004-637X/727/2/111
Abstract: We investigate mass-dependent galaxy evolution based on a large sample of (more than 50,000) K-band selected galaxies in a multi-wavelength catalog of the Subaru/XMM-Newton Deep Survey (SXDS) and the UKIRT Infrared Deep Sky Survey (UKIDSS)/Ultra Deep Survey (UDS). We employ the optical to near-infrared photometry to determine photometric redshifts of these galaxies. Then, we estimate the stellar mass of our sample galaxies using a standard fitting procedure. From the sample galaxies, we obtain the stellar mass function of galaxies and the cosmic stellar mass density up to z<4. Our results are consistent with previous studies and we find a considerable number of low-mass galaxies (M<10^{10.5}) at the redshift range 3
The Type Ia supernovae rate with Subaru/XMM-Newton Deep Survey  [PDF]
Jun E. Okumura,Yutaka Ihara,Mamoru Doi,Tomoki Morokuma,Reynald Pain,Tomonori Totani,Kyle Barbary,Naohiro Takanashi,Naoki Yasuda,Greg Aldering,Kyle Dawson,Gerson Goldhaber,Isobel Hook,Chris Lidman,Saul Perlmutter,Anthony Spadafora,Nao Suzuki,Lifan Wang
Statistics , 2014,
Abstract: We present measurements of the rates of high-redshift Type Ia supernovae derived from the Subaru/XMM-Newton Deep Survey (SXDS). We carried out repeat deep imaging observations with Suprime-Cam on the Subaru Telescope, and detected 1040 variable objects over 0.918 deg$^2$ in the Subaru/XMM-Newton Deep Field. From the imaging observations, light curves in the observed $i'$-band are constructed for all objects, and we fit the observed light curves with template light curves. Out of the 1040 variable objects detected by the SXDS, 39 objects over the redshift range $0.2 < z < 1.4$ are classified as Type Ia supernovae using the light curves. These are among the most distant SN Ia rate measurements to date. We find that the Type Ia supernova rate increase up to $z \sim 0.8$ and may then flatten at higher redshift. The rates can be fitted by a simple power law, $r_V(z)=r_0(1+z)^\alpha$ with $r_0=0.20^{+0.52}_{-0.16}$(stat.)$^{+0.26}_{-0.07}$(syst.)$\times 10^{-4} {\rm yr}^{-1}{\rm Mpc}^{-3}$, and $\alpha=2.04^{+1.84}_{-1.96}$(stat.)$^{+2.11}_{-0.86}$(syst.).
Radio imaging of the Subaru/XMM-Newton Deep Field - III. Evolution of the radio luminosity function beyond z=1  [PDF]
Chris Simpson,Steve Rawlings,Rob Ivision,Masayuki Akiyama,Omar Almaini,Emma Bradshaw,Scott Chapman,Rob Chuter,Scott Croom,Jim Dunlop,Sebastien Foucaud,Will Hartley
Physics , 2012, DOI: 10.1111/j.1365-2966.2012.20529.x
Abstract: We present spectroscopic and eleven-band photometric redshifts for galaxies in the 100-uJy Subaru/XMM-Newton Deep Field radio source sample. We find good agreement between our redshift distribution and that predicted by the SKA Simulated Skies project. We find no correlation between K-band magnitude and radio flux, but show that sources with 1.4-GHz flux densities below ~1mJy are fainter in the near-infrared than brighter radio sources at the same redshift, and we discuss the implications of this result for spectroscopically-incomplete samples where the K-z relation has been used to estimate redshifts. We use the infrared--radio correlation to separate our sample into radio-loud and radio-quiet objects and show that only radio-loud hosts have spectral energy distributions consistent with predominantly old stellar populations, although the fraction of objects displaying such properties is a decreasing function of radio luminosity. We calculate the 1.4-GHz radio luminosity function (RLF) in redshift bins to z=4 and find that the space density of radio sources increases with lookback time to z~2, with a more rapid increase for more powerful sources. We demonstrate that radio-loud and radio-quiet sources of the same radio luminosity evolve very differently. Radio-quiet sources display strong evolution to z~2 while radio-loud AGNs below the break in the radio luminosity function evolve more modestly and show hints of a decline in their space density at z>1, with this decline occurring later for lower-luminosity objects. If the radio luminosities of these sources are a function of their black hole spins then slowly-rotating black holes must have a plentiful fuel supply for longer, perhaps because they have yet to encounter the major merger that will spin them up and use the remaining gas in a major burst of star formation.
The spectroscopically confirmed X-ray cluster at z=1.62 with a possible companion in the Subaru/XMM-Newton deep field  [PDF]
Masayuki Tanaka,Alexis Finoguenov,Yoshihiro Ueda
Physics , 2010, DOI: 10.1088/2041-8205/716/2/L152
Abstract: We report on a confirmed galaxy cluster at z=1.62. We discovered two concentrations of galaxies at z~1.6 in the Subaru/XMM-Newton deep field based on deep multi-band photometric data. We made a near-IR spectroscopic follow-up observation of them and confirmed several massive galaxies at z=1.62. One of the two is associated with an extended X-ray emission at 4.5 sigma on a scale of 0'.5, which is typical of high-z clusters. The X-ray detection suggests that it is a gravitationally bound system. The other one shows a hint of an X-ray signal, but only at 1.5 sigma, and we obtained only one secure redshift at z=1.62. We are not yet sure if this is a collapsed system. The possible twins exhibit a clear red sequence at K<22 and seem to host relatively few number of faint red galaxies. Massive red galaxies are likely old galaxies -- they have colors consistent with the formation redshift of z_f=3 and a spectral fit of the brightest confirmed member yields an age of 1.8_{-0.2}^{+0.1} Gyr with a mass of 2.5_{-0.1}^{+0.2} x 10^11 M_solar. Our results show that it is feasible to detect clusters at z>1.5 in X-rays and also to perform detailed analysis of galaxies in them with the existing near-IR facilities on large telescopes.
A medium deep Chandra and Subaru survey of the 13hr XMM/ROSAT deep survey area  [PDF]
I. M. McHardy,K. F. Gunn,A. M. Newsam,K. O. Mason,M. J. Page,T. Takata,K. Sekiguchi,T. Sasseen,F. Cordova,L. R. Jones,N. Loaring
Physics , 2003, DOI: 10.1046/j.1365-8711.2003.06572.x
Abstract: We present the results of a Chandra ACIS-I survey of a high latitude region at 13h +38 which was earlier observed with ROSAT (McHardy et al. 1998) and which has recently been observed by XMM-Newton for 200ksec. XMM-Newton will provide good quality X-ray spectra for over 200 sources with fluxes around the knee of the logN/logS, which are responsible for the bulk of the X-ray background (XRB). The main aim of the Chandra observations is to provide arcsecond, or better, positions, and hence reliable identifications, for the XMM-Newton sources. The ACIS-I observations were arranged in a mosaic of four 30ksec pointings, covering almost all of the 15' radius XMM-Newton/ROSAT field. We detect 214 Chandra sources above 5 sigma significance, to a limiting flux of \~1.3e-15 erg/cm2/s (0.5-7 keV). Optical counterparts are derived from a Subaru SuprimeCam image reaching to R~27. The very large majority of the Chandra sources have an optical counterpart, with the distribution peaking at 23
Subaru Deep Survey II. Luminosity Functions and Clustering Properties of Lya Emitters at z=4.86 in the Subaru Deep Field  [PDF]
M. Ouchi,K. Shimasaku,H. Furusawa,M. Miyazaki,M. Doi,M. Hamabe,T. Hayashino,M. Kimura,K. Kodaira,Y. Komiyama,Y. Matsuda,S. Miyazaki,F. Nakata,S. Okamura,M. Sekiguchi,Y. Shioya,H. Tamura,Y. Taniguchi,M. Yagi,N. Yasuda
Physics , 2002, DOI: 10.1086/344476
Abstract: We report on early results from deep and wide-field narrow-band imaging on a 543 arcmin^2 area of the Subaru Deep Field. We find 87 Lya emitters (LAEs) at z=4.86(+/-0.03) which are photometrically selected by a combination of two broad bands (R and i') and one narrow band (NB711; 7126A FWHM=73A). We derive the luminosity functions (LFs) of the LAEs at Lya luminosity and at UV-continuum (1700A) luminosity. The LFs show little evolution between z=3.4 and z=4.86 either in Lya or UV-continuum emission. The amplitude of the LAE LF tends to decline at the bright magnitudes more rapidly than that of the LBG LF at similar redshifts. We calculate the angular correlation function of our LAEs up to ~15 arcmin separations. The angular correlation w(theta) is found to increase with decreasing angular separations, showing a clear signal of clustering. It is also found that the distribution of LAEs shows a large density gradient with a scale of >~15 arcmin, which would indicate the existence of a large-scale structure of LAEs on >~20h^(-1) Mpc scales.We fit the observed correlation function by Aw theta^(-0.8) to find Aw=29arcsec^(0.8). The estimated correlation length is r0=3.5(+/-0.3)h^(-1)Mpc in comoving units (Omega_m=0.3 and Omega_Lambda=0.7), which is slightly larger than the value for z~4 LBGs with i'<26. We calculate the angular correlation function for two sub-samples of the 87 LAEs divided by Lya luminosity, UV-continuum luminosity, and Lya equivalent width (EW). The Lya bright sub-sample shows a larger correlation amplitude than the Lya faint sub-sample, while no significant difference is found for the sub-samples divided by UV-continuum luminosity or EW.
Proper motions with Subaru II. A sample in the Subaru/XMM-Newton Deep Survey field  [PDF]
Michael W. Richmond,Tomoki Morokuma,Mamoru Doi,Yutaka Komiyama,Naoki Yasuda,Sadanori Okamura
Physics , 2009, DOI: 10.1093/pasj/62.1.91
Abstract: We search for stars with proper motions in a set of deep Subaru images, covering about 0.48 square degrees to a depth of $i' \simeq 26$, taken over a span of five and a half years. We follow the methods described in \citet{Richmond2009} to reduce and analyze this dataset. We present a sample of 69 stars with motions of high significance, and discuss briefly the populations from which they are likely drawn. Based on photometry and motions alone, we expect that 14 of the candidates may be white dwarfs. Our candidate with the largest proper motion is surprisingly faint and likely to prove interesting: its colors and motions suggest that it might be an M dwarf moving at over 500 km/sec or an L dwarf in the halo.
Lyman Alpha Emitters at z=7 in the Subaru/XMM-Newton Deep Survey Field: Photometric Candidates and Luminosity Function  [PDF]
Kazuaki Ota,Masanori Iye,Nobunari Kashikawa,Kazuhiro Shimasaku,Masami Ouchi,Tomonori Totani,Masakazu A. R. Kobayashi,Masahiro Nagashima,Atsushi Harayama,Natsuki Kodaka,Tomoki Morokuma,Hisanori Furusawa,Akito Tajitsu,Takashi Hattori
Physics , 2010, DOI: 10.1088/0004-637X/722/1/803
Abstract: We conducted a deep narrowband NB973 (FWHM = 200 A centered at 9755 A) survey of z=7 Lyman alpha emitters (LAEs) in the Subaru/XMM-Newton Deep Survey Field, using the fully depleted CCDs newly installed on the Subaru Telescope Suprime-Cam, which is twice more sensitive to z=7 Lyman alpha at ~ 1 micron than the previous CCDs. Reaching the depth 0.5 magnitude deeper than our previous survey in the Subaru Deep Field that led to the discovery of a z=6.96 LAE, we detected three probable z=7 LAE candidates. Even if all the candidates are real, the Lyman alpha luminosity function (LF) at z=7 shows a significant deficit from the LF at z=5.7 determined by previous surveys. The LAE number and Lyman alpha luminosity densities at z=7 is ~ 7.7-54% and ~5.5-39% of those at z=5.7 to the Lyman alpha line luminosity limit of L(Ly-alpha) >~ 9.2 x 10^{42} erg s^{-1}. This could be due to evolution of the LAE population at these epochs as a recent galaxy evolution model predicts that the LAE modestly evolves from z=5.7 to 7. However, even after correcting for this effect of galaxy evolution on the decrease in LAE number density, the z=7 Lyman alpha LF still shows a deficit from z=5.7 LF. This might reflect the attenuation of Lyman alpha emission by neutral hydrogen remaining at the epoch of reionization and suggests that reionization of the universe might not be complete yet at z=7. If we attribute the density deficit to reionization, the intergalactic medium (IGM) transmission for Lyman alpha photons at z=7 would be 0.4 <= T_{Ly-alpha}^{IGM} <= 1, supporting the possible higher neutral fraction at the earlier epochs at z > 6 suggested by the previous surveys of z=5.7-7 LAEs, z ~ 6 quasars and z > 6 gamma-ray bursts.
Near Infrared Faint Galaxies in the Subaru Deep Field: Comparing the Theory with Observations for Galaxy Counts, Colors, and Size Distributions to K=24.5  [PDF]
T. Totani,Y. Yoshii,F. Iwamuro,T. Maihara,K. Motohara
Physics , 2001, DOI: 10.1086/322338
Abstract: Galaxy counts in the K band, (J-K)-colors, and apparent size distributions of faint galaxies in the Subaru Deep Field (SDF) down to K~24.5 were studied in detail. Special attention has been paid to take into account various selection effects including the cosmological dimming of surface brightness, to avoid any systematic bias which may be the origin of controversy in previously published results. We also tried to be very careful about systematic model uncertainties; we present a comprehensive surveys of these systematic uncertainties and dependence on various parameters. We found that the pure luminosity evolution (PLE) model is well consistent with all the SDF data down to K~22.5, without any evidence for number or size evolution in a low-density, Lambda-dominated flat universe which is now favored by various cosmological observations. If the popular Lambda-dominated universe is taken for granted, our result then gives a strong constraint on the number evolution of giant elliptical or early-type galaxies to z~1-2 which must be met by any models in the hierarchically clustering universe, since such galaxies are the dominant population in this magnitude range (K<~22.5). In the fainter magnitude range of K>~22.5, we found a slight excess of observed counts over the prediction of the PLE model when elliptical galaxies are treated as a single population. We suggest that this discrepancy reflects some number evolution of dwarf galaxies and/or the distinct populations of giant and dwarf elliptical galaxies which have been known for local elliptical galaxies.
Page 1 /100
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.