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Proposal Identification No.:

P2817 Arecibo Observatory

Date Received: 2013-Feb-28 13:52:13 William E. Gordon Telescope Observing Time Request COVER SHEET

Section I - General Information
Submitted for Mar 1 2013. This proposal has not been submitted before. Proposal Type: General 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 Pulsars Galactic 18 0 0 45 minutes less than 100 GB

A precise measurement of the mass of PSR J1946+3414

The measurement of millisecond pulsar (MSP) masses is of great importance if we wish to better understand binary evolution scenarios and the internal structure of neutron stars (NS). In particular the discovery of massive MSPs allows for stringent limits to be placed on the equations of state of NS interiors. With this in mind, the discovery of a Galactic field MSP in a highly eccentric binary orbit, PSR J1946+3414, presents an exciting opportunity to very accurately measure the mass of an MSP. We propose a targeted observing campaign on PSR J1946+3414, the aim of which will be the detection of Shapiro delay from the system. Even a faint detection of Shapiro delay, when combined with our current advance-of-periastron measurement, will allow for a very accurate mass measuremnt of both the pulsar and its companion. Outreach Abstract: Pulsars (rapidly rotating neutron stars that beam radio emission from their magnietic poles) are produced when a suffciently massive star ( 8-10 solar masses) explodes at the end of its life. Although several properties of pulsars show that they must be composed of superfluid neutrons, we do not yet have a good understanding of their internal structure. As we cannot yet send spacecraft to investigate pulsars, we must infer their internal structure through a combination of theory and observation. Theories describing the struture of neutron stars normally have a maximum possible mass for a given radius. By measuring the mass of a pulsar, we can invalidate any theories which predict masses smaller than that measured, narrowing down the number of possible structures and bringing us a clearer understanding of neutron star interiors. To this end, we propose to accurately measure the mass of the newly discovered pulsar J1946+3414.

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Name Ewan D. Barr

Paulo C. C. Freire

Institution Max-PlanckInstitute fuer dioastronomie Max-PlanckInstitute fuer dioastronomie

E-mail ewan.d.barr@googlemail.com Rapfreire@mpifr-bonn.mpg.de Ra-

Phone +49 (0)228 525 181 +49 (0)228 525 496

Student G

no

Additional Authors
David J. Champion, davidjohnchampion@gmail.com Michael Kramer, mkramer@mpifr-bonn.mpg.de

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 I I - Time Request
The following times are in LST. For these observations night-time is not needed.

Begin ­ End Interval­Interval 18:45 ­ 20:30 19:00 ­ 20:15 19:15 ­ 20:00 ­

Days Needed at This Interval 1 4 15

Time Constraints (Must Be Justified in the Prop osal Text) Due to the high declination of the source, it is only observable for 1 hour 45 minutes per day. Although we have indicated that we wish to observe the source during transit, any time when the source is up is acceptable. The above times factor in a 15 minute setup at the beginning. 2


As stated in the full proposal, we request observations every second day for 27 days, with two extra observations when system is at superior conjunction. Furthermore, we request 5 spread out observations ( 30 mins each) across the year to improve the astrometry of the system.

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

Sp ecial Equipment or setup:

none

Section IV - RFI Considerations Frequency Ranges Planned

This proposal requires coordination with Punta Salinas radar within the band 1222-1381 MHz..

Section V - Observing List Target List
PSR J1946+3414 ; RA 19:46:25.13 ; DEC +34:17:14.71 ; LST-rise 18:55:09 ; LST-set 20:38:40

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