Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.naic.edu/~gibson/galfa/igalfa/docs/galfacts_commensal_prop2.pdf Дата изменения: Sat Feb 2 16:22:05 2008 Дата индексирования: Sat Sep 6 12:30:34 2008 Кодировка: Поисковые слова: deep sky

Proposal Identification No.: Mail hard copies to: Dr. Robert Kerr, Director Arecibo Observatory HC 3 Box 53995 Arecibo, PR 00612 U.S.A.

A

Date Received: ARECIBO OBSERVATORY NATIONAL ASTRONOMY AND IONOSPHERE CENTER OBSERVING TIME REQUEST COVER SHEET

2008-Feb-01 19:51:50

We are indebted to our user community for their continued support of the Arecibo Observatory, Puerto Rico.

Section I - General Information
Submitted for Feb 1 2008. This proposal has not been submitted before. Proposal Type: General Category: Sub-Category: Observation Category: Total Time Requested: Minimum Useful Time: Expected Data Storage: Prop osal Title: ABSTRACT: Commensal Astronomy Continuum Galactic 326.2 Hours 100-500 GB

GALFACTS Commensal Observing with I-GALFA

The GALFACTS consortium proposes to observe commensally with the I-GALFA survey (A2186). The inner Galaxy is the most important region for GALFACTS galactic disk science. While they will not replace the GALFACTS coverage of this region, the commensal observations with I-GALFA will allow the GALFACTS consortium to advance ma jor science ob jectives related to astrophysics of the magnetic field in the disk in a timely fashion. The polarimetric observations will also complement the I-GALFA HI images to allow study of the relationship between magnetic fields and the cold neutral ISM using these two Arecibo data sets. The GALFACTS data pipeline has been developed over the past two years using small pilot pro jects. With sufficient calibration observations in advance of the I-GALFA observations, we expect to be able to very rapidly turn the commensal observations into final scientific images for distribution to the GALFACTS consortium.

Name Andrew R Taylor Chris Salter Additional Authors
Tapasi Gosh (NAIC) Steven Gibson (NAIC)

Institution University of Calgary NAIC

E-mail russ@ras.ucalgary.ca csalter@naic.edu

Phone 1-403-220-5416 787-878-2612

Student no no

plus the remaining GALFACTS Consortium

(27 additional researchers).

I will not need financial support. This work is part of a PhD thesis. 1


Remote Observing Request

Observer will travel to AO X Remote Observing In Absentia (instructions to operator)

Section I I - Time Request
The following times are in AST.

Begin ­ End Interval­Interval ­ ­ ­ ­

Days Needed at This Interval

Time Constraints (Must Be Justified in the Prop osal Text) This is a commensal request. All these parameters are as for I-GALFA.

Section I I I - Instruments Needed
ALFA Atmospheric Observation Instruments:

Sp ecial Equipment or setup:

none

Section IV - RFI Considerations Frequency Ranges Planned
1270 - 1570 This proposal requires coordination with Punta Salinas radar within the band 1222-1381 MHz.. This proposal requires coordination with GPS L3 at 1381 MHz.

Section V - Observing List
2


Target List
Commensal with I-GALFA survey

3


GALFACTS Commensal Observations with I-GALFA
The GALFACTS consortium proposes to observe commensally with the I-GALFA survey (A2186). The inner Galaxy is the most important region for GALFACTS galactic disk science. While they will not replace the GALFACTS coverage of this region, the commensal observations with I-GALFA will allow the GALFACTS consortium to advance major science objectives related to astrophysics of the magnetic field in the disk in a timely fashion. The polarimetric observations will also complement the I-GALFA HI images to allow study of the relationship between magnetic fields and the cold neutral ISM using these Arecibo data sets. As an illustration of the importance of the inner Galaxy region for studies of Galactic magnetism, Figure 1 shows the Arecibo coverage of the plane of the Galaxy relative to the two interferometric polarization surveys (the CGPS and SGPS). The circles around the picture at left shows the average Faraday Rotation Measure (RM) as a function of longitude for the longitude intervals covered by the CGPS and SGPS. Filled circles indicate positive RM and open circles negative. The size of the circle scales with the magnitude of the RM. Highly structured and systematic variations in RM with longitude are seen that relate to the spiral structure of the Galaxy. The important inner Galaxy region is missing, and will be largely filled in with the GALFACTS commensal observations of I-GALFA. The GALFACTS commensal observations will yield an area density of background RM measurements several times higher than the CGPS. Thus one of the immediate science outcomes will be a nearly complete set of data on the global magnetic field structure over the entire Galaxy and on the smaller-scale "turbulent" structures in the inner galaxy, where energy injection from the products of massive star formation is high.

Figure 1. The top-down schematic of the Galaxy at left shows the coverage of polarimetric observations of the disk from the CGPS and SGPS and the Arecibo inner galaxy areas covered by I-GALFA. The surrounding circles show the average RM toward extragalactic sources through the disk of the Galaxy as a function of longitude. At right is the Arecibo sky coverage along with the CGPS and SGPS. I-GALFA covers a critical region of the inner galaxy disk that is missing from the two interferometric surveys.

GALFACTS and I-GALFA are natural commensal partners. I-GALFA uses the same fast meridian scanning observing mode that will be used for GALFACTS, albeit at a different scan speed. We carried out a pilot project in commensal mode with the GALFA HI observations in A2174. These observations were very successful and were used to refine the GALFACTS data processing pipeline. With sufficient calibration observations in advance of the I-GALFA observations, we expect to be able to very rapidly turn the commensal observations in to final scientific images for distribution to the GALFACTS consortium. The GALFACTS project has been awaiting the completion of the pdev spectrometer installation to begin the survey. We look forward to this opportunity to begin observations.