Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Nucleosynthesis wikipedia , lookup
White dwarf wikipedia , lookup
Main sequence wikipedia , lookup
Leibniz Institute for Astrophysics Potsdam wikipedia , lookup
First observation of gravitational waves wikipedia , lookup
Standard solar model wikipedia , lookup
Indian Institute of Astrophysics wikipedia , lookup
Star formation wikipedia , lookup
Astrophysical X-ray source wikipedia , lookup
Stellar evolution wikipedia , lookup
Proposal Identification No.: P3081 Date Received: 2016-Mar-03 16:11:42 Arecibo Observatory William E. Gordon Telescope Observing Time Request COVER SHEET Section I - General Information Submitted for Mar 1 2016. This proposal has not been submitted before. Proposal Type: General Category: Observation Category: Time Requested this semester: Hours Next Semester: Hours already used for this project: Additional Hours required to complete project: Minimum Useful Time: Expected Data Storage: Proposal Title: ABSTRACT: Regular Pulsars Galactic 21.25 7.5 0 1.25 hr less than 100 GB Mass and Radius of a Neutron Star NASA’s upcoming NICER mission will make a high precision (+-10%) measurement of the mass-to-radius ratio of PSR J0751+1807, a millisecond pulsar in a compact orbit with a white dwarf. We propose high-precision timing observations of this pulsar at Arecibo to refine measurements of its relativistic orbital decay, Shapiro delay, and astrometry, including proper motion and parallax. From these measurements we will be able to infer the mass of the pulsar with 4% precision. This, combined with the NICER measurement, will yield its radius to 10% precision. Both mass and radius are of fundamental importance in understanding the structure of neutron stars and the behavior of nuclear matter at high pressure. A second purpose of these observations is to provide phase tracking of the pulsar for accurate pulse-phase folding of the NICER data across its 18-month mission duration, enabling the essential X-ray pulse profile modeling required to infer the stellar mass-to-radius ratio. Outreach Abstract: An outstanding question in nuclear physics is how the matter that makes up the nuclei of atoms behaves at extremely high pressure, higher than can be produced in any laboratory on Earth. Neutron stars give us an opportunity to explore this question, as they are essentially gigantic atomic nuclei, more massive than the Sun, and have very high pressure inside. By combining measurements of a neutron star made with the Arecibo Observatory and with the NICER X-ray instrument, to be launched and installed on the International Space Station in early 2017, we will be able to measure the mass and radius of a neutron star, and hence measure the density and nature of nuclear matter at high pressure. 1 Name David J Nice Institution Lafayette College Zaven Arzoumanian E-mail [email protected] NASA Goddard Space Flight Center [email protected] Phone +1-610-3305204 +1-301-2862547 Student no no Additional Authors Ingrid Stairs, University of British Columbia, +1-604-822-6796, [email protected], not a student This work is not part of a thesis. Remote Observing Request Observer will travel to AO X Remote Observing In Absentia (instructions to operator) Section II - Time Request The following times are in LST. For these observations night-time is not needed. Begin – End Days Needed at Interval–Interval This Interval 06:30 – 09:00 6 06:30 – 07:45 5 – – Time Constraints (Must Be Justified in the Proposal Text) The six days at LST 06:30 to 09:00 should be scheduled on consecutive days, after August 20 (to avoid proximity to the Sun). The five days this semester at LST 06:30 to 07:45 should be scheduled at monthly intervals except for the month of the six-day campaign. These days may be scheduled at either 06:30 to 07:45 or 07:55 to 09:10 2 (i.e., either before or after the source transits). Next Semester Time Request Begin – End Days Needed at Interval–Interval This Interval 06:30 – 07:45 6 – – – Time Constraints (Must Be Justified in the Proposal Text) The six days this semester at LST 06:30 to 07:45 should be scheduled at monthly intervals. These days may be scheduled at either 06:30 to 07:45 or 07:55 to 09:10 (i.e., either before or after the source transits). Section III - Instruments Needed 430 G L-wide Atmospheric Observation Instruments: Special Equipment or setup: none Section IV - RFI Considerations Frequency Ranges Planned 422-442 1150-1730 This proposal requires Iridium RFI protection at 1612 MHz between 10pm and 6am EST. This proposal requires coordination with Punta Salinas radar within the band 1222-1381 MHz.. This proposal requires coordination with GPS L3 at 1381 MHz. Section V - Observing List Target List PSRJ0751+1807 07:51:09.16 +18:07:38.6 3