Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.naic.edu/vscience/schedule/2014Fall/PossentitagP2908.pdf Дата изменения: Thu Mar 6 23:00:44 2014 Дата индексирования: Mon Apr 11 16:43:28 2016 Кодировка: Поисковые слова: http www.astronomy.ru forum index.php topic 4644.0.html

Proposal Identification No.:

P2908 Arecibo Observatory

Date Received: 2014-Feb-28 19:35:09 William E. Gordon Telescope Observing Time Request COVER SHEET

Section I - General Information
Submitted for Mar 1 2014. 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 pro ject: Additional Hours required to complete pro ject: Minimum Useful Time: Expected Data Storage: Prop osal Title: ABSTRACT: Regular Pulsars Galactic 12 0 0 0 3 100-500 GB

Simultaneous X-ray/radio observations of the mode-switching PSR B0943+10

The recent discovery (Hermsen et al 2013) of variations in the X-ray flux of the pulsar PSR B0943+10, correlated with the changes in radio emission, challenged the widespread notion that the rotationpowered neutron stars are steady emitters at high energy. PSRB0943+10 is thus a key target to gain insight into the emission processes at work in the radio pulsars. In particular, two different scenarios have been put forward to interpret the X-ray timing and spectral properties of PSR B0943+10. We have successfully applied for an XMM-Newton Large Program (P.I. Mereghetti) to investigate in more detail the properties of PSR B0943+10 and 400 ks of observations have been granted. We propose to use the Arecibo radio telescope as a member of a large campaign of radio observations of PSR B0943+10 to be performed in simultaneity with the X-ray pointings. Arecibo is essential for ensuring a full coverage of the XMM-Newton observations and provide the highest quality radio data of the target. Outreach Abstract: Among the family of the neutron stars emitting pulsed signals in the radio (the so called radio pulsars) there are some ob jects showing a peculiar behavior. In particular, the intensity and the properties of their pulsed radio emission change at unpredictable times between a status of relatively low emission (called Quiet, or Q mode) and a status of strong emission (called Burst or B mode) and then back to the Quiet mode. In the case of one of these pulsars, PSRB0943+10 (discovered back in 1969), it was recently shown that this swinging behavior is reproduced also in its emission in the much more energetic X-ray band, although with opposite relative emission fluxes with respect to the radio band, i.e. at strong radio emission corresponds fainter X- ray emission while at weaker radio emission corresponds brighter X-ray emission. This unexpected behavior makes PSRB0943+10 a primary target for a deeper understanding of the still largely obscure emission mechanisms of the neutron stars.

1


Name Andrea Possenti

Sandro Mereghetti

Institution INAF-Osservatorio Astronomico di Cagliari INAF-Istituto di Astrofisica Spaziale e Fisica CosmicaMilano

E-mail possenti@oa-cagliari.inaf.it

Phone Student +3907071180228 no

sandro@iasf-milano.inaf.it

+390223699323

no

Additional Authors
Scott Ransom: sransom@nrao.edu Ramesh Bhat: ramesh.bhat@curtin.edu.au Steve Ord: ord@physics.usyd.edu.au Paolo Esposito: paoloesp@iasf-milano.inaf.it Andrea Tiengo: andrea.tiengo@iusspavia.it Roberto Turolla: turolla@pd.infn.it

This work is not part of a thesis.

Remote Observing Request

Observer will travel to AO Remote Observing X 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 08:00 ­ 11:00 ­ ­ ­

Days Needed at This Interval 4

Time Constraints (Must Be Justified in the Prop osal Text)

2


Observations should be simultaneous with XMM-Newton. These observations will take place in three or four (non consecutive) days chosen in the interval between 31 October 2014 to 04 December 2014. We expect to know the rough XMM-Newton schedule about a month in advance; exact times and dates will not be available until few days before the observations

Section I I I - Instruments Needed
327 Atmospheric Observation Instruments:

Sp ecial Equipment or setup:

none

Section IV - RFI Considerations Frequency Ranges Planned
310-340

Section V - Observing List Target List
PSRB0943+10 RA: 09:46:07.6 DEC: 09:51:55.0 LSTrise-LSTset: 08:33:41-11:00:09

3