Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.naic.edu/vscience/schedule/tpfiles/FreiretagP2391tp.pdf Дата изменения: Wed Feb 13 03:41:24 2008 Дата индексирования: Sat Sep 6 05:05:35 2008 Кодировка: Поисковые слова: http www.astronomy.ru forum index.php topic 4644.0.html

Proposal Identification No.:

P2391

Date Received:

2008-Feb-11 14:47:10

Technical Page
Proposal Type: General Category: Observation Category: Total Time Requested: Minimum Useful Time: Prop osal Title: ABSTRACT:
So far, the ALFA pulsar survey has discovered two new millisecond pulsars (MSPs), PSR J1903+0327 and PSR J1949+31. The first has a unique combination of characteristics that will allow a precise measurement of the mass of a MSP: its fast spin period (P = 2.15 ms) allows for high precision timing, its eccentric orbit (unique among MSPs in the disk of the Galaxy) has already allowed the measurement of the periastron advance, and because of its massive companion (another unique case among disk MSPs with P <9 ms) we have apparently detected the Shapiro delay. These effects point to a high pulsar mass (1.8 solar masses). Here we propose to use the high sensitivity of the Arecibo Telescope to verify the relativistic nature of these parameters and, if so, to make a precise determination of the masses of the pulsar and companion. A firm measurement of a large pulsar mass would have fundamental implications for the study of super-dense neutron matter. We also propose to observe the second MSP discovered by the ALFA pulsar survey, PSR J1949+31. It has a spin period of 13 ms and a relatively massive companion, which might allow us to measure the masses of the two components in the system using the Shapiro delay.

Long-term Pulsars Galactic 57 Hours 30 minutes

Measuring the masses of the components of two binary millisecond pulsars discovered in the ALFA pulsar survey

Name Paulo C Freire

Institution Arecibo Observatory

E-mail pfreire@remote.naic.edu

Phone Ext. 358

Student no

Remote Observing Request

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

Instrument Setup
L-wide S-low

Atmospheric Observation Instruments:

1


Sp ecial Equipment or setup:

none

RFI Considerations Frequency Ranges Planned
1120 - 1220 1360 - 1560 2700 - 3100 This proposal requires coordination with Punta Salinas radar within the band 1222-1381 MHz.. This proposal requires coordination with GPS L3 at 1381 MHz.

2