Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.naic.edu/vscience/schedule/2013Spring/GehatagA2751.pdf Дата изменения: Tue Sep 11 04:14:22 2012 Дата индексирования: Mon Feb 4 19:51:45 2013 Кодировка: Поисковые слова: sun

Proposal Identification No.:

A2751 Arecibo Observatory

Date Received: 2012-Sep-04 13:31:46 William E. Gordon Telescope Observing Time Request COVER SHEET

Section I - General Information
Submitted for Sep 1 2012. This proposal has not been submitted before. Proposal Type: General Category: Sub-Category: Observation Category: Time Requested this semester: Hours already used for this pro ject: Additional Hours required to complete pro ject: Minimum Useful Time: Expected Data Storage: Prop osal Title: ABSTRACT: Regular Astronomy Spectroscopy Extragalactic 30 0 0 30 minutes less than 100 GB

Testing Cosmology with Isolated Dwarf Galaxies

We propose HI observations of isolated low mass galaxies to better quantify the galaxy mass function. The galaxy mass function at low masses (<60 km/s) is related to the small-scale matter power spectrum, thus these observations will constrain our cosmological model, in particular the mass of the dark matter particle. While the mass function is well studied for Local Group dwarf galaxies, comparing these observations to theoretical predictions are difficult because of ram pressure and tidal stripping. By contrast, isolated dwarf galaxies are less affected by these processes. We have optically identified 73 isolated galaxies with expected low masses (between 40-60 km/s) which will nearly triple the current number of isolated galaxies with mass estimates. We request 30 hours using the L-band receiver to obtain HI observations of isolated dwarf galaxies, with the goal of robustly quantify the isolated galaxy mass function for low mass galaxies. Outreach Abstract: Our cosmological model makes detailed predictions for the relative number of large and small galaxies. The number of small galaxies around the Milky Way is far lower than predicted by this model, however, the Milky Way itself may be responsible to reducing the number of satellites around it. By contrast, we have identified a sample of isolated small galaxies. Isolated small galaxies are less affected by their surrounding environment and require less assumptions when comparing to theoretical models. We will determine the total masses of these isolated galaxies using neutral hydrogen observations in order to further test our current cosmological model.

Name Marla Geha Jeremy Bradford

Institution Yale University Yale University

E-mail marla.geha@yale.edu jeremy.bradford@yale.edu

Phone 203-432-5796

Student no G

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Additional Authors
Michael Blanton, NYU, blanton@nyu.edu,

This work is part of a PhD thesis.

Remote Observing Request

X

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

Section I I - Time Request
The following times are in LST. For these observations night-time is preferred.

Begin ­ End Interval­Interval 08:00 ­ 18:00 ­ ­ ­

Days Needed at This Interval 3

Time Constraints (Must Be Justified in the Prop osal Text) Our requested targets cover a range of RA. We prefer time to be scheduled over a 4-5 day period to facilitate travel to Arecibo for observing. However, we are also happy to observe remotely and can usefully observed in blocks as small as 30 minutes.

Section I I I - Instruments Needed
L-wide Atmospheric Observation Instruments:

Sp ecial Equipment or setup:

none

Section IV - RFI Considerations
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Frequency Ranges Planned

Section V - Observing List Target List
N RA(2000) DEC(2000) HI flux (mJy) 1 08 01 32.3 +21 22 48.3 3.5 2 08 16 52.6 +05 38 49.2 1.1 3 08 17 21.1 +24 57 45.4 4.8 4 08 26 15.0 +28 36 22.7 1.9 5 08 33 26.0 +26 51 14.0 1.4 6 08 42 36.6 +10 33 13.9 1.7 7 08 56 03.0 -00 29 21.9 1.3 8 08 57 59.9 -00 24 35.7 1.8 9 09 11 31.1 +26 37 03.7 2.7 10 09 12 23.9 +18 46 21.7 1.1 11 09 43 24.1 +21 54 51.6 1.3 12 09 47 05.7 +09 51 05.8 2.4 13 09 47 31.4 +10 29 31.7 1.4 14 09 49 19.8 +09 55 13.8 2.5 15 09 50 43.1 +09 57 02.9 1.4 16 09 58 30.2 +00 02 42.7 1.4 17 09 58 30.9 +27 16 32.2 2.8 18 10 09 40.3 +05 17 09.8 1.2 19 10 10 02.1 +17 00 34.7 1.6 20 10 24 44.2 +18 01 23.3 1.2 21 10 28 58.6 +25 17 12.8 2.4 22 10 44 36.5 +21 22 16.8 1.2 23 10 52 25.4 +21 05 30.2 3.6 24 11 06 15.8 +12 39 57.5 1.3 25 11 07 56.4 +19 46 22.0 1.6 26 11 12 52.7 +07 55 18.7 2.5 27 11 17 21.1 +15 57 14.7 1.5 28 11 28 52.1 +17 16 04.7 2.1 29 11 29 18.0 +16 48 35.1 1.3

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