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Full-Text Articles in Physical Sciences and Mathematics
New Observations Of Z~7 Galaxies: Evidence For A Patch Reionization, L. Pentericci, E. Vanzella, A. Fontana, M. Castellano, T. Treu, A. Mesinger, M. Dijkstra, A. Grazian, B. Bradac, S. Cristiani, A. Galametz, Mauro Giavalisco, E. Giallongo, R. Maiolino, D. Paris, P. Santini
New Observations Of Z~7 Galaxies: Evidence For A Patch Reionization, L. Pentericci, E. Vanzella, A. Fontana, M. Castellano, T. Treu, A. Mesinger, M. Dijkstra, A. Grazian, B. Bradac, S. Cristiani, A. Galametz, Mauro Giavalisco, E. Giallongo, R. Maiolino, D. Paris, P. Santini
Mauro Giavalisco
We present new results from our search for z∼ 7 galaxies from deep spectroscopic observations of candidate z-dropouts in the CANDELS fields. Despite the extremely low flux limits achieved by our sensitive observations, only 2 galaxies have robust redshift identifications, one from its Lyα emission line at z=6.65, the other from its Lyman-break, i.e. the continuum discontinuity at the Lyα wavelength consistent with a redshift 6.42, but with no emission line. In addition, for 23 galaxies we present deep limits in the Lyα EW derived from the non detections in ultra-deep observations. Using this new data as well as previous …
A 52 Hours Vlt/Fors2 Spectrum Of A Bright Z ~ 7 Hudf Galaxy: No Lya Emission, E. Venzella, A. Fontana, L. Pentericci, M. Castellano, A. Grazian, Mauro Giavalisco, M. Nonino, S. Cristiani, G. Zamorani, C. Vignali
A 52 Hours Vlt/Fors2 Spectrum Of A Bright Z ~ 7 Hudf Galaxy: No Lya Emission, E. Venzella, A. Fontana, L. Pentericci, M. Castellano, A. Grazian, Mauro Giavalisco, M. Nonino, S. Cristiani, G. Zamorani, C. Vignali
Mauro Giavalisco
Aims: We aim to determine the redshift of GDS_1408, the most solid z _ 7 galaxy candidate lying in the Hubble Ultra Deep Field. Methods: We have used all the VLT spectra of GDS_1408 collected by us and two other groups with FORS2 at VLT in the last five years, for a total integration time of 52hr. The combined spectrum is the deepest ever obtained of a galaxy in the Reionization epoch. Results: We do not detect any emission line or continuum over the whole wavelength range, up to 10100Å. Based on an accurate set of simulations, we are able …
The Relation Between Star Formation Rate And Stellar Mass For Galaxies At 3.5 < Z < 6.5 In Candels, Brett Salmon, Casey Papovich, Steven L. Finkelstein, Vithal Tilvi, Kristian Flinator, Peter Behroozi, Tomas Dahlen, Romeel Dave, Avishai Dekel, Mark Dickinson, Henry C. Ferguson, Mauro Giavalisco, James Long, Yu Lu, Bahram Mobasher, Naveen Reddy, Rachel S. Somerville, Risa H. Wechsler
The Relation Between Star Formation Rate And Stellar Mass For Galaxies At 3.5 < Z < 6.5 In Candels, Brett Salmon, Casey Papovich, Steven L. Finkelstein, Vithal Tilvi, Kristian Flinator, Peter Behroozi, Tomas Dahlen, Romeel Dave, Avishai Dekel, Mark Dickinson, Henry C. Ferguson, Mauro Giavalisco, James Long, Yu Lu, Bahram Mobasher, Naveen Reddy, Rachel S. Somerville, Risa H. Wechsler
Mauro Giavalisco
No abstract provided.
Aztec Half Square Degree Survey Of The Shades Fields - Ii. Identifications, Redshifts, And Evidence For Large-Scale Structure, Michał J. Michałowski, J. S. Dunlop, R. J. Ivison, M. Cirasuolo, K. I. Caputi, I. Artexaga, V. Arumugam, J. E. Austermann, E. L. Chapin, S. C. Chapman, K. E. K. Coppin, E. Egami, D. H. Hughes, E. Ibar, A. M. J. Mortier, A. M. Schael, K. S. Scott, I. Smail, T. A. Targett, J. Wagg, Grant Wilson, L. Xu, M. Yun
Aztec Half Square Degree Survey Of The Shades Fields - Ii. Identifications, Redshifts, And Evidence For Large-Scale Structure, Michał J. Michałowski, J. S. Dunlop, R. J. Ivison, M. Cirasuolo, K. I. Caputi, I. Artexaga, V. Arumugam, J. E. Austermann, E. L. Chapin, S. C. Chapman, K. E. K. Coppin, E. Egami, D. H. Hughes, E. Ibar, A. M. J. Mortier, A. M. Schael, K. S. Scott, I. Smail, T. A. Targett, J. Wagg, Grant Wilson, L. Xu, M. Yun
Grant Wilson
The AzTEC 1.1 mm survey of the SCUBA HAlf Degree Extragalactic Survey (SHADES) fields is the largest (0.7 deg2) blank-field millimetre-wavelength survey undertaken to date at a resolution of ~18" and a depth of ~1 mJy. We have used the deep optical-to-radio multi-wavelength data in the SHADES Lockman Hole East and SXDF/UDS fields to obtain galaxy identifications for ~64% (~80% with tentative identifications) of the 148 AzTEC-SHADES 1.1 mm sources, exploiting deep radio and 24 um data complemented by methods based on 8 um flux-density and red optical-infrared (i-K) colour. This unusually high identification rate can be attributed to the …
On The Detection Of Ionizing Radiation Arising From Star-Forming Galaxies At Redshift Z ~ 3-4 : Looking For Analogs Of "Stellar Reionizers", Eros Vanzella, Yicheng Guo, Mauro Giavalisco, Andrea Grazian, Marco Castellano, Stefano Cristiani, Mark Dickinson, Adriano Fontana, Mario Nonino, Emanuele Giallongo, Laura Pentericci, Audrey Galametz, S. M. Faber, Henry C. Ferguson, Norman A. Grogin, Anton M. Koekemoer, Jeffrey Newman, Brian D. Siana
On The Detection Of Ionizing Radiation Arising From Star-Forming Galaxies At Redshift Z ~ 3-4 : Looking For Analogs Of "Stellar Reionizers", Eros Vanzella, Yicheng Guo, Mauro Giavalisco, Andrea Grazian, Marco Castellano, Stefano Cristiani, Mark Dickinson, Adriano Fontana, Mario Nonino, Emanuele Giallongo, Laura Pentericci, Audrey Galametz, S. M. Faber, Henry C. Ferguson, Norman A. Grogin, Anton M. Koekemoer, Jeffrey Newman, Brian D. Siana
Mauro Giavalisco
We use the spatially-resolved, multi-band photometry in the GOODS South field acquired by the CANDELS project to constrain the nature of candidate Lyman continuum (LyC) emitters at redshift z~3.7 identified using ultra-deep imaging below the Lyman limit (1-sigma limit of ~30 AB in a 2" diameter aperture). In 18 candidates, out of a sample of 19 with flux detected at >3-sigma level, the light centroid of the candidate LyC emission is offset from that of the LBG by up to 1.5". We fit the SED of the LyC candidates to spectral population synthesis models to measure photometric redshifts and the …
A Detailed Study Of Photometric Redshifts For Goods-South Galaxies, Tomas Dahlen, Bahram Mobasher, Mark Dickinson, Henry C. Ferguson, Mauro Giavalisco, Norman A. Grogin, Yicheng Guo, Anton Koekemoer, Kyoung-Soo Lee, Seong-Kook Lee, Mario Nonino, Adam G. Reiss, Sara Salimbeni
A Detailed Study Of Photometric Redshifts For Goods-South Galaxies, Tomas Dahlen, Bahram Mobasher, Mark Dickinson, Henry C. Ferguson, Mauro Giavalisco, Norman A. Grogin, Yicheng Guo, Anton Koekemoer, Kyoung-Soo Lee, Seong-Kook Lee, Mario Nonino, Adam G. Reiss, Sara Salimbeni
Mauro Giavalisco
We use the deepest and the most comprehensive photometric data currently available for GOODS-South galaxies to measure their photometric redshifts. The photometry includes VLT/VIMOS (U-band), HST/ACS (F435W, F606W, F775W, and F850LP bands), VLT/ISAAC (J-, H-, and Ks-bands), and four Spitzer/IRAC channels (3.6, 4.5, 5.8, and 8.0 micron). The catalog is selected in the z-band (F850LP) and photometry in each band is carried out using the recently completed TFIT algorithm, which performs PSF matched photometry uniformly across different instruments and filters, despite large variations in PSFs and pixel scales. Photometric redshifts are derived using the GOODZ code, which is based on …
Spectroscopic Confirmation Of Z~7 Lbgs: Probing The Earliest Galaxies And The Epoch Of Reionization, L. Pentericci, A. Fontana, E. Vanzella, M. Castellano, A. Grazian, M. Dijkstra, K. Boustia, S. Cristiani, M. Dickinson, E. Giallongo, Mauro Giavalisco, R. Maiolino, A. Moorwood, P. Santini
Spectroscopic Confirmation Of Z~7 Lbgs: Probing The Earliest Galaxies And The Epoch Of Reionization, L. Pentericci, A. Fontana, E. Vanzella, M. Castellano, A. Grazian, M. Dijkstra, K. Boustia, S. Cristiani, M. Dickinson, E. Giallongo, Mauro Giavalisco, R. Maiolino, A. Moorwood, P. Santini
Mauro Giavalisco
We present the final results from our ultra-deep spectroscopic campaign with FORS2 at the ESO/VLT for the confirmation of z~7 "z--band dropout" candidates selected from our VLT/Hawk-I imaging survey over three independent fields. In particular we report on two newly discovered galaxies at redshift ~6.7 in the NTT deep field: both galaxies show a Ly-alpha emission line with rest-frame EWs of the order 15-20 A and luminosities of 2-4 X 10^{42} erg/s. We also present the results of ultra-deep observations of a sample of i-dropout galaxies, from which we set a solid upper limit on the fraction of interlopers. Out …
The Lack Of Intense Lyman~Alpha In Ultradeep Spectra Of Z=7 Candidates In Goods-S: Imprint Of Reionization?, A. Fontana, E. Vanzella, L. Pentericci, M. Castellano, Mauro Giavalisco, A. Grazian, K. Boutsia, S. Christiani, M. Dickinson, E. Giallongo, M. Maiolino, A. Moorwood, P. Santini
The Lack Of Intense Lyman~Alpha In Ultradeep Spectra Of Z=7 Candidates In Goods-S: Imprint Of Reionization?, A. Fontana, E. Vanzella, L. Pentericci, M. Castellano, Mauro Giavalisco, A. Grazian, K. Boutsia, S. Christiani, M. Dickinson, E. Giallongo, M. Maiolino, A. Moorwood, P. Santini
Mauro Giavalisco
We present ultradeep optical spectroscopy obtained with FORS2 on VLT of seven Lyman-break galaxy (LBG) candidates at z>6.5 selected in the GOODS-S field from Hawk-I/VLT and WFC3/HST imaging. For one galaxy we detect a low significance emission line (S/N< 7), located at 9691.5 +/- 0.5A and with flux 3.4 x 10^(-18)erg/cm^2/s. If identified as Lyman alpha, it places the LBG at redshift z=6.972+/- 0.002, with a rest-frame equivalent width EW}=13A. Using Monte Carlo simulations and conservative EW distribution functions at 210 is ~ 2%, and that of observing only one galaxy out of seven with S/N=5 is ~4%, but these can be as small as ~1E-3, depending on the details of the EW distribution. We conclude that either a significant fraction of the candidates is not at high redshift or that some physical mechanism quenches the Lyman alpha emission emerging from the galaxies at z>6.5, abruptly reversing the trend of the increasing fraction of strong emitters with increasing redshift observed up to z~ 6.5. We discuss the possibility that an increasingly neutral intergalactic medium is responsible for such quenching.
Spectroscopic Confirmation Of Two Lyman Break Galaxies At Redshift Beyond 7, E. Vanzella, L. Pentericci, A. Fontana, A. Grazian, M. Castellano, K. Boutsia, S. Cristiani, M. Dickinson, S. Gallozzi, E. Giallongo, Mauro Giavalisco, R. Maiolino, A. Moorwood, D. Paris, P. Santini
Spectroscopic Confirmation Of Two Lyman Break Galaxies At Redshift Beyond 7, E. Vanzella, L. Pentericci, A. Fontana, A. Grazian, M. Castellano, K. Boutsia, S. Cristiani, M. Dickinson, S. Gallozzi, E. Giallongo, Mauro Giavalisco, R. Maiolino, A. Moorwood, D. Paris, P. Santini
Mauro Giavalisco
We report the spectroscopic confirmation of two Lyman break galaxies at redshift > 7. The galaxies were observed as part of an ultra-deep spectroscopic campaign with FORS2 at the ESO/VLT for the confirmation of z~7 ``z--band dropout'' candidates selected from our VLT/Hawk-I imaging survey. Both galaxies show a prominent emission line at 9735A and 9858A respectively: the lines have fluxes of ~ 1.6-1.2 x 10^(-17) erg/s/cm2 and exhibit a sharp decline on the blue side and a tail on the red side. The asymmetry is quantitatively comparable to the observed asymmetry in z ~ 6 Ly-alpha lines, where absorption by neutral …
The Great Observatories Origins Deep Survey: Constraints On The Lyman Continuum Escape Fraction Distribution Of Lyman--Break Galaxies At 3.4, E. Vanzella, Mauro Giavalisco, A. Inoue, M. Nonino, F. Fontanot, S. Cristiani, A. Grazian, M. Dickinson, D. Stern, P. Tozzi, E. Giallongo, H. Ferguson, H. Spinrad, K. Boutsia, A. Fontana, P. Rosati
The Great Observatories Origins Deep Survey: Constraints On The Lyman Continuum Escape Fraction Distribution Of Lyman--Break Galaxies At 3.4, E. Vanzella, Mauro Giavalisco, A. Inoue, M. Nonino, F. Fontanot, S. Cristiani, A. Grazian, M. Dickinson, D. Stern, P. Tozzi, E. Giallongo, H. Ferguson, H. Spinrad, K. Boutsia, A. Fontana, P. Rosati
Mauro Giavalisco
We use ultra-deep ultraviolet VLT/VIMOS intermediate-band and VLT/FORS1 narrow-band imaging in the GOODS Southern field to derive limits on the distribution of the escape fraction (f_esc) of ionizing radiation for L >~ L*(z=3) Lyman Break Galaxies (LBGs) at redshift 3.4--4.5. Only one LBG, at redshift z=3.795, is detected in its Lyman continuum (LyC; S/N~5.5), the highest redshift galaxy currently known with a direct detection. Its ultraviolet morphology is quite compact (R_eff=0.8, kpc physical). Three out of seven AGN are also detected in their LyC, including one at redshift z=3.951 and z850 = 26.1. From stacked data (LBGs) we set an …
Evidence Of A Fast Evolution Of The Uv Luminosity Function Beyond Redshift 6 From A Deep Hawk-I Survey Of The Goods-S Field, M Castellano, A Fontana, K Boutsia, A Grazian, L Pentericci, R Bouwens, M Dickinson, M Giavalisco, P Santini, S Cristiani, Et. Al.
Evidence Of A Fast Evolution Of The Uv Luminosity Function Beyond Redshift 6 From A Deep Hawk-I Survey Of The Goods-S Field, M Castellano, A Fontana, K Boutsia, A Grazian, L Pentericci, R Bouwens, M Dickinson, M Giavalisco, P Santini, S Cristiani, Et. Al.
Astronomy Department Faculty Publication Series
No abstract provided.
Spectroscopic Observations Of Lyman-Break Galaxies At Redshift ~ 4, 5 And 6 In The Goods-South Field, E. Vanzella, Mauro Giavalisco, M. Dickinson, S. Cristiani, M. Nonino, H. Kuntschner, P. Popesso, P, Rosati, A. Renzini, D. Stern, C. Cesarsky, H. C. Ferguson, R. A. E. Fosbury, The Goods Team
Spectroscopic Observations Of Lyman-Break Galaxies At Redshift ~ 4, 5 And 6 In The Goods-South Field, E. Vanzella, Mauro Giavalisco, M. Dickinson, S. Cristiani, M. Nonino, H. Kuntschner, P. Popesso, P, Rosati, A. Renzini, D. Stern, C. Cesarsky, H. C. Ferguson, R. A. E. Fosbury, The Goods Team
Mauro Giavalisco
We report on observations of Lyman-break galaxies (LBGs) selected from the Great Observatories Origins Deep Survey at mean redshift z~4, 5 and 6, obtained with FORS2 spectrograph at the ESO-VLT.This program has yielded spectroscopic identifications for 114 galaxies of which 51 are at z~4, 31 at z~5, and 32 at z~6. The adopted selection criteria are effective, identifying galaxies at the expected redshift with minimal foreground contamination. Once selection effects are properly accounted for, the rest-frame UV spectra of the higher-redshift LBGs appear to be similar to their counterparts at z~3. As at z~3, LBGs at z~4 and z~5 show …
Photometric Properties Of Ly Alpha Emitters At Z=4.86 In The Cosmos 2 Square Degree Field, Y. Shioya, Y. Taniguchi, S. S. Sasaki, T. Nagao, T. Murayama, T. Saito, Y. Ideue, A. Nakajima, K. L. Matsuoka, J. Trump, N. Z. Scoville, D. B. Sanders, B. Mobasher, H. Aussel, P. Capak, J. Kartaltepe, A. Koekemoer, C. Carilli, R. S. Ellis, B. Garilli, Mauro Giavalisco, M. G. Kitzbichler, C. Impey, O. Lefevre, E. Schinnerer, V. Smolcic
Photometric Properties Of Ly Alpha Emitters At Z=4.86 In The Cosmos 2 Square Degree Field, Y. Shioya, Y. Taniguchi, S. S. Sasaki, T. Nagao, T. Murayama, T. Saito, Y. Ideue, A. Nakajima, K. L. Matsuoka, J. Trump, N. Z. Scoville, D. B. Sanders, B. Mobasher, H. Aussel, P. Capak, J. Kartaltepe, A. Koekemoer, C. Carilli, R. S. Ellis, B. Garilli, Mauro Giavalisco, M. G. Kitzbichler, C. Impey, O. Lefevre, E. Schinnerer, V. Smolcic
Mauro Giavalisco
We present results of a survey for Ly alpha emitters at z=4.86 based on optical narrowband (lambda_c=7126 angstrom, Delta lambda=73 angstrom) and broadband (B, V, r', i', and z') observations of the Cosmic Evolution Survey (COSMOS) field using Suprime-Cam on the Subaru Telescope. We find 79 LAE candidates at z=4.86 over a contiguous survey area of 1.83 deg^2, down to the Ly alpha line flux of 1.47 x 10^-17 ergs s^-1 cm^-2. We obtain the Ly alpha luminosity function with a best-fit Schechter parameters of log L^*=42.9^+0.5_-0.3 ergs s^-1 and phi^* = 1.2^+8.0_-1.1 x 10^-4 Mpc^-3 for alpha=-1.5 (fixed). The …
Spectroscopic Observations Of Lyman Break Galaxies At Redshifts Similar To 4, 5, And 6 In The Goods-South Field, E Vanzella, M Giavalisco, M Dickinson, S Cristiani, M Nonino, H Kuntschner, P Popesso, P Rosati, A Renzini, D Stern, C Cesarsky, Hc Ferguson, Rae Fosbury
Spectroscopic Observations Of Lyman Break Galaxies At Redshifts Similar To 4, 5, And 6 In The Goods-South Field, E Vanzella, M Giavalisco, M Dickinson, S Cristiani, M Nonino, H Kuntschner, P Popesso, P Rosati, A Renzini, D Stern, C Cesarsky, Hc Ferguson, Rae Fosbury
Astronomy Department Faculty Publication Series
We report on observations of Lyman-break galaxies (LBGs) selected from the Great Observatories Origins Deep Survey at mean redshift z~4, 5 and 6, obtained with FORS2 spectrograph at the ESO-VLT.This program has yielded spectroscopic identifications for 114 galaxies of which 51 are at z~4, 31 at z~5, and 32 at z~6. The adopted selection criteria are effective, identifying galaxies at the expected redshift with minimal foreground contamination. Once selection effects are properly accounted for, the rest-frame UV spectra of the higher-redshift LBGs appear to be similar to their counterparts at z~3. As at z~3, LBGs at z~4 and z~5 show …
The Scatter In The Relationship Between Redshift And The Radio-To-Submm Spectral Index, C L. Carilli, Min S. Yun
The Scatter In The Relationship Between Redshift And The Radio-To-Submm Spectral Index, C L. Carilli, Min S. Yun
Min S. Yun
We derive the scatter in the relationship between redshift and the radio-to-submillimeter spectral index, a135.40, using the observed spectral energy distributions of 17 low-redshift star-forming galaxies. A mean galaxy model is derived, along with the rms scatter in a13.540. The scatter is roughly constant with redshift. Constant rms scatter, combined with the Ñattening of the mean a13.540-z relationship with increasing redshift, leads to increasing uncertainty for redshift estimates at high redshifts. Normalizing by the dust temperature in the manner proposed by Blain decreases the scatter in a13.540 for most of the sample, but does not remove outliers, and free-free absorption …
Detection Of Co (2-1) And Radio Continuum Emission From The Z = 4.4 Qso Bri 1335–0417, C L. Carilli, Karl M. Menten, Min S. Yun
Detection Of Co (2-1) And Radio Continuum Emission From The Z = 4.4 Qso Bri 1335–0417, C L. Carilli, Karl M. Menten, Min S. Yun
Min S. Yun
We have detected redshifted CO (2-1) emission at 43 GHz and radio continuum emission at 1.47 and 4.86 GHz from the z = 4.4 QSO BRI 1335-0417 using the Very Large Array. The CO data imply optically thick emission from warm (>30 K) molecular gas with a total mass, M(H2), of (1.5 ± 0.3) × 1011 Msun, using the standard Galactic gas mass-to-CO luminosity conversion factor. We set an upper limit to the CO source size of 1farcs1 and a lower limit of 0farcs23(Tex/50 K)-1/2, where Tex is the gas excitation temperature. We derive an upper limit to the …
The Radio-To-Submillimeter Spectral Index As A Redshift Indicator, C L. Carilli, Min S. Yun
The Radio-To-Submillimeter Spectral Index As A Redshift Indicator, C L. Carilli, Min S. Yun
Min S. Yun
We present models of the 1.4 to 350 GHz spectral index 350 for starburst galaxies as a function of redshift. a1.4 The models include a semianalytic formulation, based on the well-quantified radio–to–far-infrared correlation for low-redshift star-forming galaxies, and an empirical formulation, based on the observed spectrum of the starburst galaxies M82 and Arp 220. We compare the models to the observed values of 350 for starburst galaxies at low a1.4 and high redshift. We find reasonable agreement between the models and the observations and, in particular, that an observed spectral index of 350 indicates that the target source is likely …