Post on 06-Feb-2018
SO04 (WD, Terada)
Welcome to our Session (SO04) !
Photo in City Hole Stockholm, 3 July 2012 reception
The parallel session of 13th Marcel Grossmann Meeting
White Dwarf Pulsars and Rotating White Dwarf Theory
SO04 (WD, Terada)
Scope of this session Original Simple Question Why we do not have White Dwarf Pulsars? Related Questions How can we feedback to Neutron Star Science? (structure of magnetosphere, emission mechanism, death line, diversity of NSs)
What is the impact on Astrophysics? (Origin of Cosmic-rays: 100 years celebration from the discovery !)
What is the impact to extreme physics? (Internal structure, Equation of state, of white dwarfs)
The parallel session of 13th Marcel Grossmann Meeting
White Dwarf Pulsars and Rotating White Dwarf Theory
To answer them is the scope of ...
5 July 2012 The 13th Marcel Grossmann Meeting, Stockholm 2012
2 / 21
SO04 (WD, Terada)
Goal of this session
Shareing our knowledge on white dwarfs Discussion on topics (5 min per talk)
Working together important Interactions between our tasks in this field is important! 1. Know each other 2. Making working group (or mailing list) to exchange information
3. Do not miss the dead line of proceedings, on 28 Feb 2013 !
5 July 2012 The 13th Marcel Grossmann Meeting, Stockholm 2012
3 / 21
Review on High Energy observations in searches for Non-thermal emissions
from Accelerated particles in Magnetic White Dwarfs
Yukikatsu Terada (Saitama University, Japan)
SO04 (WD, Terada)
1. Review on white dwarf pulsars
5 July 2012 The 13th Marcel Grossmann Meeting, Stockholm 2012
5 / 21
SO04 (WD, Terada)
Simple Idea: similarity between NS and WD
WDs can accelerate particles showing non-thermal emission.
White Dwarf Pulsar
5 July 2012 The 13th Marcel Grossmann Meeting, Stockholm 2012
6 / 21
SO04 (WD, Terada)
First Proposal of WD pulsar in 1969
• Original interest was the ORIGIN of COSMIC-RAY. (NS cannot generate low-energy particles in GeV, only WD can do.)
Same year as the pulsar theory by Goldreich and Julian 1969
1969 ICRC
5 July 2012 The 13th Marcel Grossmann Meeting, Stockholm 2012
7 / 21
SO04 (WD, Terada)
First estimation of the contribution to CR 1971 ICRC
CR heavy ions
CR electrons 1971 ICRC
5 July 2012 The 13th Marcel Grossmann Meeting, Stockholm 2012
8 / 21
SO04 (WD, Terada)
Found in the Hillas diagram Makishima 2008
Emax = e v B L ~ 6x1016(P/1s)-1(B/1012G)(L/106cm)2 eV (NS)
So, the idea of WD Pulsar should be quite natural .
5 July 2012 The 13th Marcel Grossmann Meeting, Stockholm 2012
9 / 21
MWD
Maxim
um E
nerg
y (
eV)
Blazer
Magnetic CVs
Globular Cluster
Solar flare
Winter thander
Crab
Magnetic storm
Inversive Magnetic Pinch
SO04 (WD, Terada)
Observational approaches in 1980-1990s Radio Survey • Non-thermal incoherent radio emissions found in 7 WDs (Nelson&Spencer 88, Beasley+ 94, Pavelin+94, Bond+02, Mason&Gray 07) • Coherent radio emissions from AE Aqr and AM Her
(Bastian+88, Abada-Simon+93, Chanmugam&Dulk 82,Dulk+83) Suggesting 1-100 MeV electrons
Gamma-ray survey • AE Aqrii is listed among 5 sources in the first TeV catalog. (Currently NOT) • First detection of TeV from AE Aqr (Meintjes+92, 93) and AM Her (Bhat+91) in flare • Many Report of TeV detections from AE Aqr, independently (Bowden+92 ,Chadwick +95)
• No confirmation with long observation by Whipple (Lang+98)
Difficulties in “Single dish, non-imaging ” γ-ray telescopes
No WD Pulsars ??
5 July 2012 The 13th Marcel Grossmann Meeting, Stockholm 2012
10 / 21
Whipple
SO04 (WD, Terada)
Theoretical predictions in 1990-2000s Interpretation as “mille-second pulsar” equivalent (de Jager 94)
• Idea for a magnetic white dwarf binary, AE Aqr. • High Spin down (33 s, 10-13 s/s, Lsd = 6 x 1033 erg/s) (de Jager+ 94, Mauche+06) • Low accretion, no disk, propeller effect (Wynn+97) to make lower than nGJ
Interpretation of high spin down luminosity of AE Aqr • High magnetic field strength (Bs = 50MG) (Ikhsanov 98, 99) • Verification by Doppler Hα tomogram (Ikhsanov+ 04, Ikhsanov and Beskrovnaya 08) • Estimation of X-ray and Gamma-ray from AE Aqr (Ikhsanov and Biermann 06)
Based on standard NS pulsar theories. + Magnetic reconnection.
Idea of “magnetars” equivalent? • Why we have so many diverse in NSs? • WDs comes in magnetars area
(Terada & Dotani 11) Lbol > Ldp ? (Lbl ~ 0.1% of Lsd )
• New Class of magnetic CVs? (Ikhsanov & Beskrovnaya 12)
• Magnetars as MWD? (Malheiro+12)
5 July 2012 The 13th Marcel Grossmann Meeting, Stockholm 2012
11 / 21
SO04 (WD, Terada)
Observational searches,again, after 2005 Discovery of non-thermal Radio (Zhang & Gil 05)
•radio transient in Galactic Center region, GCRT J1745-3009
Searches for non-thermal emission in X-ray • Suzaku discovery of hard X-ray pulsation (Terada +08) (later)
Searches for non-thermal emission in TeV gamma-ray band
• No TeV emission with MAGIC (Sidro+08) • Simultaneous campaign of AE Aqr with Chandra & MAGIC (Mauche+11 ) • Simultaneous campaign of AE Aqr with Suzaku & H.E.S.S. (Terada+) (later)
5 July 2012 The 13th Marcel Grossmann Meeting, Stockholm 2012
12 / 21
SO04 (WD, Terada)
2. Suzaku searches for non-thermal emission from WDs.
Collaborators: Y. Terada, A. Harayama (Saitama Univ. Japan), T. Hayashi, T. Dogtani, M. Ishida (ISAS/JAXA, Japan), A. Bamba (Aoyama Gakuin, Jp), K. Makishima (U.Tokyo, Jp), K. Mukai (NASA/GSFC, USA), Y. Urata (Taiwan Cent Univ, Taiwan), A. Nitta (Gemini Observatory, USA), Okkie de Jager(North-West Univ, South Africa), Paula Chadwick(Durham Univ, UK) , Stefan Wagner(LSW, Germany), David Buckley(Univ.of Cape Town, South Africa)
5 July 2012 The 13th Marcel Grossmann Meeting, Stockholm 2012
13 / 21
SO04 (WD, Terada)
Breakthrough: Suzaku discovery of hints
Neutron Star (Crab)
White Dwarf (AE Aqr)
Enhances at soft X-ray flares
(1) Sharp Pulse profile like NSs!
Object: AE Aqr (Intermediate Polar) Suzaku observation: Oct 2005 (SWG), 70 ksec
Terada+ 2008
5 July 2012 The 13th Marcel Grossmann Meeting, Stockholm 2012
14 / 21
SO04 (WD, Terada)
Spectral property of the Hard X-ray pulses
Phase resolved spectra
(2) No Thermal lines in the Pulse spectrum in over 2 keV band.
Peak
Becker and Trumper 1999 Possenti et al 2002
Luminosity of Pulse component
AE Aqr
Spin down energy (erg/s) X-
ray
Flux
(erg
/s)
(3) Similar photon index and fraction to spin down energy as NS case
Possible non-thermal emission from AE Aqr
5 July 2012 The 13th Marcel Grossmann Meeting, Stockholm 2012 15
SO04 (WD, Terada)
Isolated WDs ① Known P and B, highest Ldp, EUVE J0317-85.5 (2010, 60 ks)
② ROSAT candidate, EUVE J1439 +75.0 (2012, 40 ks)
③ ROSAT candidate, PG 1658 +440 (2012, 50 ks)
And beyond.. Binary system (MCVs) ① Another TeV source, AM Her, in low state (2008, 100 ks) (Terada +10)
② Simultaneous observation of AE Aqr with Optical + Suzaku + H.E.S.S.(2009, ToO 160ks) (Next Viewgraph)
③ hard catalog by INTEGRAL, IGRJ00234+6141 (2010, 80 ks)
④ hard catalog in Swift BAT, V2487 Oph (2010, 50 ks) thermal
Pulsar Non-thermal?
E ※ Rejection of thermal emission is the key for searches
Harayama talk
star accretion wd
Hayashi talk
NS WD
ms pulsars AE Aqr, MCVs
Radio pulsars Isolated WDs?
(de Jager 94)
5 July 2012 The 13th Marcel Grossmann Meeting, Stockholm 2012
16 / 21
SO04 (WD, Terada)
Multi-wave campaign of AE Aqr • First Guest observation with H.E.S.S (8 hr, 6 nights) • Long observation with Suzaku(net 160 ksec, 400 ksec in total), • Optical telescope network • Date: 14 – 21 Oct, 2009
5 July 2012 The 13th Marcel Grossmann Meeting, Stockholm 2012
17 / 21
SO04 (WD, Terada)
Results in multi-wave campaign • [Gamma] Very short exposure with H.E.S.S., due to bad weather • [X] Suzaku observation was competed (5 days!) • [Opt] bad weather, but partially overlapping with Suzaku
Light Curve in X-ray
Several flares in X-ray Good correlation between X-opt, especially for soft X-rays
Energy (keV) Time (s)
Flare
Soft
X
Hard
X
1000 s
Optical
Soft
X-ra
y C
ross-col.
0.7 – 3 keV
Optial
SAAO
Turkey
<2keV
>2keV
1 day
0.5-1 keV
1-2 keV
2-4keV
4-6 keV
6-10keV
5 July 2012 The 13th Marcel Grossmann Meeting, Stockholm 2012
18 / 21
SO04 (WD, Terada)
X-ray spectra
Top/Bottom
Pulsed
Fe
Ne, Fe Mg
Ar S
Si O
•Phase resolved X-ray spectra with Suzaku (70 ksec+50 ksec+160 ksec)
Top & Bottom
No plasma lines in PULSED spectrum Non thermal !!
1.8x1030 erg/s @102pc 0.5-10keV = 0.5% of LSD(confirmed)
5 July 2012 The 13th Marcel Grossmann Meeting, Stockholm 2012
19 / 21
SO04 (WD, Terada)
3. Summary List of Questions
5 July 2012 The 13th Marcel Grossmann Meeting, Stockholm 2012
20 / 21
SO04 (WD, Terada)
List of questions to you all in this room Do we really have WD pulsars?
• Please show current observational attempts (Terada, Hayashi, Harayama, Meregetti) • Please show plans with newly born and/or near future missions (Kitaguchi, others) • Can we expect non-thermal emissions from WD pulsars? Death line?(Wada, Ikhsanov) • Is it Pulsar-like emission and/or PWN-like emission?
Can we feedback to NS pulsar science?
• What is the similarity between NS and WD? Especially for magnetars? (Malheiro, Coelho, Achille) • What is the difference between NS and WD? (Wada) • Do we have some hints on question why we have so many kinds of NS pulsars, when they are simply rotating magnets? (all)
What is the impact to astrophysics ? (Origin of cosmic-rays, 100 years from the discovery)
• Electron and positron source? (Kashiyama) What is the impact to extreme physics? (Internal structure of WDs)
• What is the internal structure of WD. (Boshkayev, Simonetta, Upasana, Sheyse)
Let’s start and enjoy the session !!
5 July 2012 The 13th Marcel Grossmann Meeting, Stockholm 2012
21 / 21