Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.naic.edu/vscience/schedule/tpfiles/HezarehtagA2708tp.pdf Дата изменения: Tue Oct 1 18:52:16 2013 Дата индексирования: Mon Apr 11 16:35:06 2016 Кодировка: Поисковые слова: molecular cloud

Proposal Identification No.:

A2708

Date Received:

2013-Sep-03 08:46:48

Technical Page
This proposal has been submitted before. The previous proposal number is a2708. Proposal Type: General Category: Sub-Category: Observation Category: Total Time Requested: Minimum Useful Time: Prop osal Title: ABSTRACT: Regular Astronomy Spectroscopy Galactic 28 Hours 3 hours

Zeeman Measurements of OH Spectral lines in Starless Clouds

The fragmentation of molecular clouds and the formation of cores are still intensely debated issues. Measuring the ratio of mass-to-magnetic-flux ratio in a core to its value in the envelope can help distinguish between the competing theories (ambipolar-diffusion vs. turbulence). Crutcher et al. (2009) performed this measurement by combining Zeeman detections in OH lines in dense cores (using Arecibo) with upper limits in the envelopes of their sources (using GBT). However, the choice of envelope locations with the GBT beam hampered the fair sampling of the envelope field. Moreover, the statistical validity of this analysis is currently disputed. We improve this experiment with OH Zeeman measurements in the envelope of a single dark core, L1544, to better reveal how the magnetic field changes across the core and envelope. We have used 21 hours of a total of required 49 hours, and we request the remaining time to finish the pro ject.

Name Talayeh Hezareh

Institution Max Planck Institut fuer Radioastronomie

E-mail thezareh@mpifr-bonn.mpg.de

Phone +49-228-525392

Student no

Remote Observing Request

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

Instrument Setup
L-wide

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Atmospheric Observation Instruments:

Sp ecial Equipment or setup: Since we will be performing circular polarization observations, we require to cross correlate the native linearly polarized signals from the L-Wide feed, both directly and through a 90 degree phase shift, to get Stokes I and V as outputs.

RFI Considerations Frequency Ranges Planned
1665 - 1720

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