Welcome to the Osservatorio Astronomico di Roma and the Astro-GR/VESF School
Pau Amaro Seoane, Raffaella Schneider, Luigi Stella
A brief summary of studies at OAR related to GWs
- Magnetars - Double White Dwarf Binaries - Short Gamma Ray Bursts - Stochastics GW background - E.M. Follow up programs - eLISA sources and Athena
The B-field of Magnetars Very strong internal B-fields in a newborn differentially rotating fast-spinning neutron star For initial spin periods of Pi∼1–2 ms, differential rotation can store ∼1052(Pi/1 ms)2 ergs, that can be converted into a magnetic field of up to 3x1017 (Pi/1ms)-1 G. (efficient dynamo might be limited to ~3x1016 G) (Duncan & Thompson 1992)
Bd Bt
Bd ~ 1014-15 G outer dipole field (spin-down, pulsations) inferred from spin-down rate (and confirmed through the energetics and fast variability properties of the “ringing tail” of Giant Flares from SGRs) Bt > 1015 G inner toroidal field (energy reservoir): lower limit from: L(persistent) x age ~ 1047 ergs
Fast spin (few ms) and differential rotation generate
internal toroidal field B > 1015 G
Magnetars: Bursts
- energy release ~1038-1041 ergs - subsecond duration - often emitted in bunches
SGR 1806-20: Giant Flare of 2004 Dec 27
(Mereghetti et al. 2005)
(Palmer et al. 2005 Hurley et al. 2005)
Moon reverberation seen !
First detection of Quasi Periodic Oscillation in a Magnetar
Total power spectrum of XTE high resolution data
XTE was observing a cluster of galaxies, a constant and low “background” level for the SGR1806-20 hyperflare
Newborn Magnetars as Gravitaional Wave Sources
(for Virgo Cluster distance, 20 Mpc) - GW signal at ~1 kHz evolving in 1 week - Consider initial spin period of 2ms Most promising region is Bt > 1016.5 G and Bd < 1014 G - Required no. of templates is very large Expected magnetar birth rate in the ~2000 galaxies of Virgo: ~ 1 yr-1 ! Potentially Very Interesting GW Event Rate in Advanced LIGO/Virgo-class instruments
2x1016 G 6x1016 G
~ 1 week, ~ 108cycles
Nov 2002 Nov 2001
RXJ0806.3+1527: a double degenerate binary system (2WDs) with an orbital period of 5.4min !! One of the best target for gravitational wave calibration with eLISA
Double White Dwarf Binaries (AM CVn-like)
Short Gamma-Ray Bursts
• GRBs duration distribution is bimodal (e.g. Briggs et al. 2002) – 0.1-1 s -> Short bursts – 10-100 s -> Long bursts
• Short GRBs are harder than long GRBs
(e.g. Fishman & Meegan, 1995;Tavani 1996).
Swift
BAT Burst Image
T<10 s, θ < 4'
1. Burst Alert Telescope triggers on GRB, calculates position to < 4 arcmin 2. Spacecraft autonomously slews to GRB position in 20-70 s 3. X-ray Telescope determines position to < 5 arcseconds 4. UV/Optical Telescope images field, transmits finding chart to ground
BAT Error Circle
XRT Image
T<100 s, θ < 5''
T<300 s
UVOT Image
Instrumentation Burst alert telescope (BAT) 10-150 keV X-ray telescope (XRT) 0.3-10 keV
UV-optical telescope (UVOT) U-I
- USA, I, UK mission dedicated to GRB Science
Coalescing binary models
Association of Short GRBs to low SFR galaxies + absence of SN : Merging (or Coalescing) binary models for Short GRBs
Neutron Star + Neutron star (NS-NS) or Neutron Star + Black hole (NS-BH) Strong Gravitational Wave Sources !
2014 Astro-GR/VESF School
- Emphasis on the astrophysical counterparts of gravitational wave (GW) sources and events; required to confirm GW detections
- Bring together the high frequency (Virgo/LIGO) and low frequency (eLISA) GW communities
- Advanced Virgo and LIGO operational in a few years: ~100 deg^2 error regions expected by the late 2010’s
- Astro-GR Meeting and VESF school merged this year: aiming at cross-fertilisation across different communities (GWs, Ap), while also teaching young scientists and students.
Astro-GR Meeting Series
• The scope of VESF is promo1ng the physics of gravita1onal waves,and the collabora1on among groups in different countries
-‐> VESF goals and func1ons revised; main aims: -‐ to foster the par1cipa1on of a larger community, especially in the field of data analysis ( -‐ to help coordinate and run mul1messenger programs (see enthusias1c response to the MoU call)
• In 2008 VESF was composed of 48 groups, ~ 200 members from Virgo, ~ 200 non-‐
Virgo members belonging to European universi1es, laboratories and astronomical observatories.
-‐> New census necessary: will begin in July 2014
-‐ All groups to reply (or apply) -‐ revision of par1cipant list and LoI -‐ 1 VESF Council representa1ve per group with > 3 people
The Virgo EGO Science Forum (VESF) in the Advanced Detector Era
VESF Schools (2012 -‐> )
• 2012 – “VESF School on Advanced Gravita1onal Wave Detectors” – Held at Virgo Site Cascina – Jan 18-‐22. 18 Par1cipants
• 2013 -‐ VESF School on ”Gravita1onal waves, neutrinos and mul1wavelenght
e.m. observa1ons: the new fron1er of astronomy”, held at INAF-‐OAR in Monteporzio Catone (Italy) -‐ April 15-‐18.
35 Par1cipants, 18 speakers
• 2014 – VESF School (run jointly with ASTRO-‐GR) “Astrophysics of low and high frequency Gravita1onal Waves”
to be held at INAF-‐OAR in Monteporzio Catone (Rome, Italy) –July 14-‐18. ~30 Par1cipants, 22 speakers • 2015 – two VESF Schools planned in collabora1on with GRAWITON ITN
* April/May – General School, Virgo Site Cascina (Italy) * Nov -‐-‐ Data Analysis School, Birmingham (UK)
• 2016 – TBD (in collabora1on with NewCompStar and GRAWITON)
Financial support from - EGO/VESF - INAF (Italian National Institute of Astropshyics) - Albert Einstein Institute
Logistics - Coffee breaks/lunches: 2^ floor - Vending Machines: basement - Wireless: TBD - Transportation - Different room tomorrow ?
How does it work: - we divide in 4 groups, 1 group per day - each group picks up a person to give a summary talk on Friday
Group 2 - Tuesday Imma Donnarumma Massimo Dotti Andrés Escala Viviana Fafone Alessia Franchini Felipe Garrido Bruno Giacomazzo Giuseppe Greco Leonardo Gualtieri Jafar Khodagholizadeh Diana Lumaca
group 1 - Monday Lorenzo Aiello Tal Alexander Pau Amaro-Seoane Manuel Arca Sedda Stefano Ascenzi Maria Grazia Bernardini Marica Branchesi Igor Bulyzhenkov Jordi Casanellas Claudio Casentini Sabrina D’Antonio Simone Dall’Osso
Groups 3 - Wednesday Michela Mapelli Stefania Marassi Francesca Marchi Andrea Maselli Simone Mastrogiovanni Cristián Maureira Fredes Cristiano Palomba Paolo Pani Andrea Passamonti Silvia Piranomonte Nataliya Porayko Andrea Possenti
Group 4 - Thursday Alessio Rocchi Elena Maria Rossi Sabina Sabatini Raffaella Schneider Bernard Schutz Alberto Sesana Günter Sigl Mario Spera Adamantios Stavridis Luigi Stella Ian Vega Andrea Vicere Brunetto Ziosi
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