Nina Tetzlaff, Ralph Neuhäuser, Markus M. Hohle Baha Dincel(AIU Jena)

Transcription

1 Nina Tetzlaff, Ralph Neuhäuser, Markus M. Hohle Baha Dincel(AIU Jena) Bonn Workshop 2013 Monday, 15 April 2013

2 Motivation

3 Motivation 90 % [Kuranov, Popov & Postnov 2009] 10 % disrupted binary isolated neutron star + runaway star remain bound NS + companion

4 Motivation goal: identify potential placeswere supernovaeoccurred in the (recent) past therefore tracing back in time young neutron stars [e.g. ATNF pulsar database], runaway stars [catalogue: Tetzlaff et al. 2011a]and young associations/ clusters(also bubbles, SNR...) (Monte Carlo simulations) find close encounterswith young associations/ clusters and/ or runaway stars hitting the jackpot: find neutron star/ runaway pair very precise SN location, timeat which it occurred and distance to Earth

5 Motivation Why? Determine precise ages of cooling neutron stars (kinematic ages τ kin better represent true NS age than spin-down ages) τ kin & T eff compared with cooling curves

6 Neutron star cooling kinematic ages (boxes) better fit with cooling curves than characteristic ages (symbols) superfluidneutrons, protons; G, massesof M (fromtopto bottom) (courtesy A.D. Kaminker, see also Gusakov et al. 2005) e.g. RX J : τ char = 3.8 Myr τ kin 0.5 Myr RX J : τ char = 1.9 Myr τ kin 0.8 Myr (will be again addressed later) (τ char fromatnf pulsardatabase) log 10 (age [Myr]) Bonn Workshop

7 Motivation Why? Determine precise ages of cooling neutron stars (kinematic ages τ kin better represent true NS age than spin-down ages) τ kin & T eff compared with cooling curves (need more ages for better statistics) estimate mass of NS progenitor (from progenitor lifetime) with SN distance and time: probe SN (ejecta) models, SN yields identify former companions binary evolution Tracing back runaway stars may eventually lead to finding more (young, cooling, radio-quiet) neutron stars Predict regions with enhanced number of NSs input for gravitational wave searches

8 Motivation Cam/CasCep Cyg Per Sco Cen Vela Ori Supernova rate within 600 pc from the Sun (courtesy J. Schmidt) normalized supernova rate [#/7.2 deg 2 /10 Myr] Trajectories (up to 1 Myr in the past) of young neutron stars (red) and massive runaway stars (blue). Contour lines: 26 Al 1.8 MeV COMPTEL map (Diehl et al. 2010). 15/04/2013

9 Motivation one or more supernovaexplosions close to the Solar systemin therecent past [e.g. Maíz-Appellániz 2001, Berghöfer & Breitschwerdt 2002, Fernández et al. 2008] formation & reheating of the Local Bubble, SN triggered star formation(sco-cen, young local associations) [e.g. de Geus 1992, Preibisch & Zinnecker 1999, 2007, Berghöfer & Breitschwerdt 2002, Fernández et al. 2008] deposits of SN produced radionuclides on Earth[Ellis et al. 1996] 60 Fefound in the Earth s crust [Knie et al. 1999, 2004, Fitoussi 2008] from Maíz-Apellániz 2001 Local Bubble(black lines) (Na I distribution dark: higher density) black: Knie et al. 2004, green: Fitoussiet al. 2008, recomputedfornew 10 Be half life (courtesyj. Feige)

10 Results RX J

11 Results RX J only probable birth association: Upper Scorpius(US) τ 0.48 Myr = present supernova position with respect to the Sun: distance 155 pc, coordinates: l 350, b smallradial velocity( 6 km/s) = - 20 consistent with observed bow shock (inclinationwrtthelineof sightcloseto 90, van Kerkwijk& Kulkarni 2001) no former companion candidate found v r direction of motion RX J approximate shape of bowshock

12 Results RX J Implication: life time of progenitorstar= age of US (5 Myr, e.g. Preibischet al. 2002) minus kinematic age +30 stellar evolutionarymodels: massof theprogenitorstar28-64 M (O7-B0) +15 earlier spectral type than earliest present member of US: B0V (HIP 81266) present(theoretical) size of supernova remnant: radius 47 pc(17 ) 26 Al 1.8 MeV COMPTEL map: withhalf-lifeof 26 Al (0.72 Myr) an ejectedmassof 26 Al of M isobtained massof theprogenitorstar(fromyieldmodels): 60-80M

13 Results RX J

14 Results RX J nine possible birth associations(due to large distance error for the neutron star) borneithernearbyorin Trumpler10 best former companion candidate: HIP (B0II/III) then originated from Trumpler ± 0.2 Myr ago presentpositionof predictedsupernovawrtthesun: distance 380 pc, coordinates: l 260, b 2.4

15 Results RX J Implication: life time of progenitorstar= age of Trumpler10 (15-35 Myr, de Zeeuwet al. 1999, Loktin& Beshenov2001, Kharchenkoet al. 2005) minus kinematicage stellar evolutionarymodels: massof theprogenitorstar 7-15 M (B1-B2/3) earlierspectraltypethanearliestpresentmembersof Tr10: 3 B3 stars rotationalvelocityof HIP relativelylarge (vsini= 96 ±15 km/s) estimationof theprogenitormassbymeansof 26 Al notfeasiblesincesupernova position too close to galactic plane

16 Results 20 Further Nearby Neutron Stars

17 Results 20 Further Nearby Neutron Stars 12 of themprobablyformedwithin500 pcfromthesun 7 neutron stars possibly born in the Solar neighbourhood (Scorpius-Centaurus, younglocalassociations) 60 Fe? former companion candidates found for 11 neutron stars

18 superfluidneutrons, protons; G, neutronstarmass1.32 M massesof M (fromtopto bottom) (courtesy A.D. Kaminker, see Gusakov et al. 2005) magnetic field strengths of G (frombottomto top) (courtesyj. Pons, seealso Ponset al. 2009, Popovet al. 2010) dashed: toroidal + poloidal field solid: toroidal field symbols: characteristic ages boxes: kinematic age ranges

19 Conclusions and Outlook

20 Conclusions and Outlook itiswell feasibleto determinethebirthplaceof a neutronstarand its kinematic age if the observables are sufficiently precise in many cases no unique birth place, hence other indicators necessary former companion(runaway star) 26 Al confirmationof radial velocity, e.g. bymeansof a bowshock 40 former companion candidates proposed follow-up observations needed(radial velocity, indications for a past supernova event, indications for evolution in a former binary system)

21 Thank you for your attention!