| 1. Identity statement | |
| Reference Type | Journal Article |
| Site | mtc-m16b.sid.inpe.br |
| Holder Code | isadg {BR SPINPE} ibi 8JMKD3MGPCW/3DT298S |
| Identifier | 6qtX3pFwXQZGivnK2Y/QqndG |
| Repository | sid.inpe.br/mtc-m17@80/2007/06.11.13.33 |
| Last Update | 2007:06.11.13.33.51 (UTC) administrator |
| Metadata Repository | sid.inpe.br/mtc-m17@80/2007/06.11.13.33.52 |
| Metadata Last Update | 2018:06.05.03.34.15 (UTC) administrator |
| Secondary Key | INPE--PRE/ |
| ISSN | 1365-2966 |
| Citation Key | GuimarãesPRCDSAC:2007:EvOvAr |
| Title | Evidence for overdensity around zem > 4 quasars from the proximity effect  |
| Year | 2007 |
| Month | may |
| Access Date | 2024, May 16 |
| Secondary Type | PRE PI |
| Number of Files | 1 |
| Size | 432 KiB |
| 2. Context | |
| Author | 1 Guimarães, R. 2 Petitjean, P. 3 Rollinde, E. 4 Carvalho, Reinaldo Ramos de 5 Djorgovski, S. G. 6 Srianand, R. 7 Aghaee, A. 8 Castro, S. |
| Resume Identifier | 1 2 3 4 8JMKD3MGP5W/3C9JJ5B |
| Group | 1 2 3 4 DAS-INPE-MCT-BR |
| Affiliation | 1 Observatorio Nacional (ON) 2 Institut d’Astrophysique de Paris & Universit´e Pierre et Marie Curie 3 Observatoire de Paris 4 Instituto Nacional de Pesquisas Espaciais (INPE) 5 Palomar Observatory 6 Inter University Centre for Astronomy and Astrophysics (IUCAA) 7 University of Sistan and Baluchestan 8 European Southern Observatory |
| Journal | Monthly Notices of the Royal Astronomical Society |
| Volume | 377 |
| Pages | 657-666 |
| History (UTC) | 2007-06-29 19:12:15 :: rosemary -> simone :: 2007-12-19 14:12:56 :: simone -> administrator :: 2012-10-23 23:53:27 :: administrator -> simone :: 2007 2013-02-20 15:19:58 :: simone -> administrator :: 2007 2018-06-05 03:34:15 :: administrator -> marciana :: 2007 |
| 3. Content and structure | |
| Is the master or a copy? | is the master |
| Content Stage | completed |
| Transferable | 1 |
| Content Type | External Contribution |
| Keywords | Methods: data analysis Methods: statistical Galaxies: Clusters: general Quasars: absorption lines Dark matter ASTROPHYSICS |
| Abstract | We study the density field around zem > 4 quasars using high-quality medium spectral resolution Echelle Spectrograph and ImagerKeck spectra (R ∼ 4300, signal-to-noise ratio (S/N) > 25) of 45 high-redshift quasars selected from a total of 95 spectra. This large sample considerably increases the statistics compared to previous studies. The redshift evolution of the mean photoionization rate and the median optical depth of the intergalactic medium (IGM) are derived statistically from the observed transmitted flux and the pixel optical depth probability distribution function, respectively. This is used to study the so-called proximity effect, that is, the observed decrease of the median optical depth of the IGM in the vicinity of the quasar caused by enhanced photoionization rate due to photons emitted by the quasar. We show that the proximity effect is correlated with the luminosity of the quasars, as expected. By comparing the observed decrease of the median optical depth with the theoretical expectation, we find that the optical depth does not decrease as rapidly as expected when approaching the quasar if the gas in its vicinity is part of the standard IGM.We interpret this effect as revealing gaseous overdensities on scales as large as ∼15 h−1 Mpc. The mean overdensity is of the order of 2 and 5 within, respectively, 10 and 3 h−1 Mpc. If true, this would indicate that high-redshift quasars are located in the centre of overdense regions that could evolve with time into massive clusters of galaxies. The overdensity is correlated with luminosity: brighter quasars show higher overdensities.. |
| Area | CEA |
| Arrangement | urlib.net > BDMCI > Fonds > Produção anterior à 2021 > DIDAS > Evidence for overdensity... |
| doc Directory Content | access |
| source Directory Content | there are no files |
| agreement Directory Content | there are no files |
| 4. Conditions of access and use | |
| data URL | http://mtc-m16b.sid.inpe.br/ibi/6qtX3pFwXQZGivnK2Y/QqndG |
| zipped data URL | http://mtc-m16b.sid.inpe.br/zip/6qtX3pFwXQZGivnK2Y/QqndG |
| Language | en |
| Target File | Evidence for overdensity.pdf |
| User Group | administrator rosemary simone |
| Visibility | shown |
| Archiving Policy | allowpublisher allowfinaldraft |
| Read Permission | allow from all |
| 5. Allied materials | |
| Next Higher Units | 8JMKD3MGPCW/3ETR8EH |
| Citing Item List | sid.inpe.br/mtc-m21/2012/07.13.14.58.48 1 |
| Dissemination | WEBSCI; PORTALCAPES; MGA; COMPENDEX. |
| Host Collection | lcp.inpe.br/ignes/2004/02.12.18.39 cptec.inpe.br/walmeida/2003/04.25.17.12 |
| 6. Notes | |
| Empty Fields | alternatejournal archivist callnumber copyholder copyright creatorhistory descriptionlevel documentstage doi e-mailaddress electronicmailaddress format isbn label lineage mark mirrorrepository nextedition notes number orcid parameterlist parentrepositories previousedition previouslowerunit progress project readergroup rightsholder schedulinginformation secondarydate secondarymark session shorttitle sponsor subject tertiarymark tertiarytype typeofwork url versiontype |
| 7. Description control | |
| e-Mail (login) | marciana |
| update | |