1 / 11

A Proposed VLA Band - 190 MHz Pathfinder Study for the EOR L. Greenhill (CfA)

A Proposed VLA Band - 190 MHz Pathfinder Study for the EOR L. Greenhill (CfA). Basic Goals Detection of HI shells around “EOR quasars” Exploration of line brightness fluctuations over ~10 ( ° )2 Explore noise-limited deep imaging Befriend galactic foregrounds Status

reagan-luna
Download Presentation

A Proposed VLA Band - 190 MHz Pathfinder Study for the EOR L. Greenhill (CfA)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. A Proposed VLA Band - 190 MHz Pathfinder Study for the EORL. Greenhill (CfA) • Basic Goals • Detection of HI shells around “EOR quasars” • Exploration of line brightness fluctuations over ~10(°)2 • Explore noise-limited deep imaging • Befriend galactic foregrounds • Status • Funding approved by Smithsonian (October 1) • US$110K • Leverages previous investments in the VLA • Now under peer review by NRAO • Technical/management review to begin Dec. 04 • Proposed tracks in late 2005, early 2007. • Permanent addition to the VLA. Legacy science.

  2. Key VLA/VHF Science Questions • What are the shapes/sizes of the HII regions? • How anisotropic is the ionizing radiation? • When did the quasars form after recombination? • What is the nature of the IGM at z~6.3? • When did Tspin exceed TCMB? • What is the reionization history? • Constrain the neutral fraction at z~ 6.3 Pathfinder program w/r to foreground elimination and assessment of gross signal strength (case A/B). Co-Is: Blundell, Loeb, Zaldarriaga (CfA),Carilli, Perley (NRAO), Furlanetto (CalTech)

  3. Strong Signal Case and (more likely) Weak Signal Case

  4. How Strong is Strong - How Weak is Weak? 295 mK (Wyithe & Loeb) • Initial target list: 3 SDSS quasars (z=6.2-6.4) that show a “depth effect” to the Lya absorption (Fan et al.). • The HI lines will lie at 192-196 MHz.

  5. The Sky at 408 MHz Haslam et al. 1982 Adapted by Emerson Tsky = 14-16 K (408 MHz) => ~110 K (194 MHz)

  6. Placement of Proposed VHF Receivers Although Ae(327 MHz) ~ 0.40, Ae(VHF) ~ 0.50 !

  7. Schematic Layout for VHF Rx Test of strong signal case and technical demo 50h per source in 2005. The proposed VHF system is opti-mized for sensitivity more so than existing 4m and 0.9 m systems.

  8. Radio Spectrum Allocation

  9. RFI at the VLA Site Clear sky TV Carrier Lightning Monitoring continues. Winter observing

  10. Timeline • Oct. 04 - Observing proposal • Jan. 05 - First prototype delivered • Mar. 05 - Four prototypes deployed • Jun. 05 - 14 Rx delivered • Jul. 05 - 14 Rx delivered • Late 05 - 1st D-config. and 1st “useful” data • Early 07 - 2nd D-config.

  11. System Specifications • Dipole - parabolic dish hybrid • Eases calibration • Bandwidth - 186 - 202 MHz (1.6 m) • Primary beam - 4.3° • Synthesized beam - 5-15´ (D-config.) • Tsys ~ 180 K • Ae ~ 0.5 ( ~6600 m2) • Sensitivity ~ 10 mK in 50h • Crossed dipole system l/3 from focus • Invisibility

More Related