ISM Studies Towards Magnetars (An Update) Magnetar Visualisation, - - PowerPoint PPT Presentation

Jarryd Hawkes

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Adelaide University ISM Studies Towards Magnetars Nanten2 Workshop 2015

ISM Studies Towards Magnetars

(An Update)

Magnetar Visualisation, credit ESO

Jarryd Hawkes

In collaboration with G. Rowell, B. Dawson, M. Burton, Y. Fukui

Jarryd Hawkes

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Adelaide University ISM Studies Towards Magnetars Nanten2 Workshop 2015

• Background
• Survey purpose and outline
• Results so far

...Since last time:

– Bad 7mm data retaken (1647, 1708, 0526) – 12mm data taken and processed

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Adelaide University ISM Studies Towards Magnetars Nanten2 Workshop 2015

What are they?

• Previously made up of two classes of object – AXPs and SGRs

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Exhibit both persistant and bursting/flaring x-ray emission

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Period 2-12 seconds, 10-12 - 10-10 s/s

• Luminosities in soft and hard X-rays are greater than their

rotational energy loss

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Thought to be powered by their intense magnetic field (>1014 G)

Black dots - radio pulsars, red symbols - all known magnetars

From N. Rea et al. 2012 ApJ 754 27

˙ P

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Adelaide University ISM Studies Towards Magnetars Nanten2 Workshop 2015

Why look at them?

• Search for link between magnetars and TeV gamma-ray emission and

investigate their emission mechanisms and energetics

• Unknown whether magnetars are able to accelerate particles to TeV

energies.

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Spin down power of magnetars ~1032-34 erg/s, but magnetic dissipation effects may yield luminosity of ~1035-36 erg/s (Zhang 2003, In Proc)

• Look for evidence of the impact of magnetars on the ISM

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As high energy objects with extreme B fields, we expect high energy outflows

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High energy emission traced by disturbance of the ISM

• Emission from shocked and disrupted gas
• Dense gas / TeV associations

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Discrimination between hadronic / leptonic

• rigin of gamma-rays

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Clues to the acceleration processes in the region

Jarryd Hawkes

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Adelaide University ISM Studies Towards Magnetars Nanten2 Workshop 2015

Why look at them?

• Understand the environment & ways in which these objects are

formed

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Magnetars thought to be born to high mass progenitors, many found in massive stellar clusters

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High spin-down rates of magnetars imply they are young objects (<105 yrs)

• Currently 8 of 25 magnetars found

towards visible SNRs

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So, look for evidence of star formation towards magnetars in the ISM

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Dense gas/magnetar associations may allow for precise distance estimates

• Better luminosity and age estimates

CXOU J171405.7-381031

From Aharonian et al. (2008) A&A, 486, 829

γ-ray excess, MGPS contours

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Adelaide University ISM Studies Towards Magnetars Nanten2 Workshop 2015

Targeted Campaign

• Utilizing the Mopra radio telescope
• Deep pointings towards each magnetar in the 7mm and 12mm

bands

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1x30 min On/Off pointing

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Tracers targeted:

• CS, NH3, ... -> Cold, dense gas (density, optical depth, temperature)
• SiO, CH3OH, H2O, ... -> Star formation, outflows, shocked gas
• RRLs -> Ionised Gas (HII regions)
• Follow-up mapping of sources with

emission to reveal gas morphology and any relation to nearby objects

• Also looking at molecular/atomic

carbon data from the Nanten, MopraCO and HEAT CI surveys

Credit ATNF

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Adelaide University ISM Studies Towards Magnetars Nanten2 Workshop 2015

Catalogue / Observed Emission

• 25 (known + candidates)

Purple: Candidate Magnetars Grey: Unobservable from the southern hemisphere Source: McGill Online Magnetar Catalogue www.physics.mcgill.ca/~pulsar/magnetar/main.html

Source Name Emission Association

SGR1801-23 CS ... HESS J1800-240B /W28 SGR1806-20 CS W31, MC 13A, massive star cluster HESS J1808-204 XTEJ1810-197 ... HESS J1809-193 AXJ1818.8-1559 ... SNR G15.4+0.1 SGRJ1822.3-1606 CS M17 (HII region) LS 5039/HESS J1825-137 SGRJ1834.9-0846 CS, NH3(1,1),(3,3), C2S, H2O SNR W41 HESS J1834-087 SGR1833-0832 CS ... HESS J1834-087 1E1841-045 CS HESS J1841-055 AXJ1845-0258 SNR G29.6+0.1 HESS J1848-018 SGR1900+14 massive star cluster HESS J1912+101 SGR2013+34 W58 (giant HII complex) ... 1E2259+586 SNR CTB 109 Cassiopeia A 4U0142+61 ... ... SGR0418+5729 ... ... SGR0501+4516 SNR HB9 ... SGR0526-66 LMC, SNR N49, SL 463 N157B? 1E1048.1-5937 GSH 288.3-0.5-2.8 (stellar wind bubble) HESS J1026-582 CXOUJ010043.1-721134 SMC ... 1E1547.0-5408 SNR G327.24-0.13 HESS J1614-518 PSRJ1622-4950 SNR G333.9+0.0 HESS J1626-490 SGR1627-41 CS, NH3(1,1),(2,2),(3,3), CTB 33 (radio complex), MC -71, HESS J1634-472 H2O, C2S? H69a? SNR G337.0-0.1 CXOJ164710.2-455216 CS 1RXSJ170849.0-400910 ... HESS J1708-410 CXOUJ171405.7-381031 SNR CTB 37B, HESS J1713-381 CTB 37B SGRJ1745-2900

Nearby TeV region

SNR Kes 73 Westerlund 1 (massive star cluster) Westerlund 1 HESS J1646-458 Galactic Center, Sgr A* Galactic Centre

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Adelaide University ISM Studies Towards Magnetars Nanten2 Workshop 2015

Results So Far

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Adelaide University ISM Studies Towards Magnetars Nanten2 Workshop 2015

SGR 1627-41

SGR 1627-41

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Located nearby to extended TeV gamma-ray regions HESS J1632-478 / HESS J1634-472 and associated with HII complex CTB 33 at 11.0 kpc

(Corbel et al. 1999, ApJ, 526, 29)

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CS at -119 & -75 km/s -> 6.8/8.9 & 4.8/10.9 kpc (near/far)

Preliminary

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Adelaide University ISM Studies Towards Magnetars Nanten2 Workshop 2015

SGR 1627-41

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NH3 seen at the same velocities

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Broad NH3 (~16 km/s) at -75 km/s gives column density ~8.0E-21 cm-3, Tkin ~ 26 K

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NH3 at -119 km/s gives column density ~ 7.7E-21 cm-3, Tkin ~ 20 K

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Determine relationship between magnetar & gas/HII region & TeV emission

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Adelaide University ISM Studies Towards Magnetars Nanten2 Workshop 2015

SGR 1806-20

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Lies towards TeV region HESS J1808-204, together with massive stellar cluster C1 1806-20. The cluster includes LBV 1806-20, which may power coincident radio nebula G10.3-0.3 (Gaensler et al., 2001, ApJ,

559, 963) –

TeV luminosity of 1.2x1034 erg/s can be accounted for by the energetics of the stellar winds from the cluster or LBV 1806-20 alone, or magnetic energy from SGR 1806-20 (Rowell et al., 2012, AIP Conf Proc, 1505, 273)

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Range of distance estimates

From Rowell et al., AIP Conference Proceedings, 1505, 273 (2012)

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Adelaide University ISM Studies Towards Magnetars Nanten2 Workshop 2015

SGR 1806-20

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70 km/s cloud in Nanten 12CO data covers the TeV emission, peaks towards its centre and is a good morphological match

• Candidate for hadronic gamma-ray production

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Obtain gas parameters, use ages of objects and extent of TeV emission to perform particle diffusion analysis

• Determine hadronic/leptonic gamma-ray production, origin of gamma-rays

Nanten 12CO From 70 – 82 km/s Preliminary

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Adelaide University ISM Studies Towards Magnetars Nanten2 Workshop 2015

Swift J1834.9-0846

Possible association with SNR W41 and/or HESS J1834-087

(Kargaltsev 2012, ApJ, 748, 26)

• Origin of TeV emission again

ambiguous (PWN/SNR-MC interaction/Magnetar)

X-ray and radio image from Kargaltsev et al. (2012)

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Adelaide University ISM Studies Towards Magnetars Nanten2 Workshop 2015

Swift J1834.9-0846

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CS emission at the same velocity as 13CO associated with the SNR (Leahy and Tain, 2008, AJ, 135, 167)

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CS cloud (radius 2.3') to the south west

• f the SGR, within the TeV region
• Virial mass of cloud 3 – 11 x103

solar masses (at 4.2 kpc)

Preliminary

Mopra CS(J=1-0) From 74 – 78 km/s

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Adelaide University ISM Studies Towards Magnetars Nanten2 Workshop 2015

Swift J1834.9-0846

• NH3(1,1) and C2S indicates dense >104 cm-3

molecular gas

• NH3 same width and profile as CS
• Possible NH3(3,3)
• H2O maser emission

star formation →

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Adelaide University ISM Studies Towards Magnetars Nanten2 Workshop 2015

1E1841-045

1E1841-045

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Associated with SNR Kes 73

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Distance currently estimated from HI absorption features at 7.5-9.4 kpc (Tian, W. and Leahy, D., 2008, ApJ, 677, 292)

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If the narrow CS emission at 98 km/s is associated with the AXP/SNR, we constrain the distance to the object at 9.3 +- 0.1 kpc, which allows for more precise age and luminosity estimates

Chandra Image, from H. S. Kumar et al. (2013), PotIAU, 9, pp 235-238

1E1841-045

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Adelaide University ISM Studies Towards Magnetars Nanten2 Workshop 2015

1E1547.0-5408

Distance of ~9 kpc based on DM

(Camilo et al. 2007, ApJ, 666, 93)

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Association with SNR G327.24-0.13

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HI absorption / RRL measurements to radio sources in the same star forming region places it at ~4 kpc

(Gelfand & Gaensler, 2007, ApJ, 667, 1111)

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CS at -57 km/s -> 3.7/10.7 kpc

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Adelaide University ISM Studies Towards Magnetars Nanten2 Workshop 2015

CXO J164710.2-455216

• Part of massive stellar cluster Westerlund 1

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Magnetar a possibility for origin of TeV emission seen towards the cluster (HESS J1646–458)

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Distance 4.3 kpc based on HI line emission

• CS seen at -32 km/s

2.5/11.8 kpc (near/far) →

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Adelaide University ISM Studies Towards Magnetars Nanten2 Workshop 2015

SGR 1833-0832

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Not associated with any high energy emission/SNRs

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CS at 54 km/s -> 3.8/11.9 kpc: Possible parent molecular cloud? SGR 1801-23

• Located nearby to SNR W28 and

TeV source HESS J1801-23

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CS peak at 6.6 km/s 1.6/13.6 → kpc (near/far), SNR between 1.2-3.3 kpc

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Adelaide University ISM Studies Towards Magnetars Nanten2 Workshop 2015

Summary

• Surveying the ISM towards magnetars is set to reveal key information

needed to better understand these rare and energetic objects, in particular their formation, evolution and emission processes

• We have already seen evidence of dense gas towards magnetars,

which:

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Correspond to or even constrain the accepted distance

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Have potential for gamma-ray production

• Possibly more mapping
• Calculations of gas parameters, distances and modelling of particle

propagation to determine ages, energetics and gamma-ray origins

• Assessing each magnetar's potential for high-energy emission

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Possible follow up gamma-ray observations with HESSII?

Future Work

Jarryd Hawkes

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Adelaide University ISM Studies Towards Magnetars Nanten2 Workshop 2015

Stayed tuned for updates and results! Thanks for listening