Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.naic.edu/vscience/schedule/tpfiles/GIOVANARDItagA2231tp.pdf Дата изменения: Tue Aug 15 22:44:45 2006 Дата индексирования: Sat Dec 22 23:58:55 2007 Кодировка: Поисковые слова: http astrokuban.info astrokuban

Proposal Identification No.:

A2231

Date Received:

2006-May-30 12:44:48

Technical Page
Proposal Type: General Category: Sub-Category: Observation Category: Total Time Requested: Minimum Useful Time: Prop osal Title: ABSTRACT: Regular Astronomy Spectroscopy Extragalactic 52 Hours 1 hour

The Faint Disk and Clouds in the Outskirts of M33

We propose to use the ALFA array to map, in the 21-cm line, two fields around the Local Group galaxy M33, the largest galaxy in angular extent observable at Arecibo. We will reach a sensitivity of about 10**18 atoms per sq. cm or 10**4 Msun (!), at a resolution of 1-2 km/s, that is a substantial improvement respect to any previous search with comparable spectral and spatial resolution. The selected region is 5 square deg. and extends from the outer disk out to a pro jected radius of 55 kpc. The HI data will provide unique information on topics of cosmological importance: i) the presence of infalling gas clouds and of dark satellites, that is compact HI clouds with an associated dwarf dark-matter halo; ii) the position and structure of the outer edge of the HI disk and thus the intensity and relevance of the extragalactic ionizing background radiation; iii) the outermost disk warp, together with the density structure of the M33 dark-matter halo beyond 15 disk scalelengths (20 kpc) and its possible connection with M31. The proximity of M33, and the availability of a sensitive L-band array, provide therefore a rare opportunity to probe the nature of dark matter by unveiling its distribution at very large galactocentric distances and by testing in the Local Universe scenarios of continuing galaxy formation through infall and merging.

Name CARLO GIOVANARDI

Institution INAF Osservatorio Arcetri Firenze ITALY

E-mail giova@arcetri.astro.it

Phone ++39 055 2752 239

Student

Remote Observing Request

X

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

Instrument Setup
ALFA 1


Atmospheric Observation Instruments:

Sp ecial Equipment or setup:

none

RFI Considerations Frequency Ranges Planned

2