Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.naic.edu/vscience/schedule/tpfiles/FreiretagP2391tp.ps Дата изменения: Wed Feb 13 03:41:18 2008 Дата индексирования: Sat Sep 6 04:45:53 2008 Кодировка: Поисковые слова: п п п п п п п п п п п п п п п п п п п п п п п п п п п п

Proposal Identification No.: P2391 Date Received: 2008­Feb­11 14:47:10
Technical Page
Proposal Type: Long­term
General Category: Pulsars
Observation Category: Galactic
Total Time Requested: 57 Hours
Minimum Useful Time: 30 minutes
Proposal Title: Measuring the masses of the components of two binary millisecond pulsars
discovered in the ALFA pulsar survey
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 e#ects 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 super­dense 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.
Name Institution E­mail Phone Student
Paulo C Freire Arecibo Observatory pfreire@remote.naic.edu Ext. 358 no
Remote Observing Request
Observer will travel to AO
X Remote Observing
In Absentia (instructions to oper­
ator)
Instrument Setup
L­wide S­low
Atmospheric Observation Instruments:
1

Special 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 1222­1381 MHz..
This proposal requires coordination with GPS L3 at 1381 MHz.
2