Gavin Rowell High Energy Astrophysics Group, School of Physical - - PowerPoint PPT Presentation

http://www.physics.adelaide.edu.au/astrophysics/MopraGam/

Gavin Rowell

High Energy Astrophysics Group, School of Physical Sciences University of Adelaide

Nanten2 Meeting (UWS, Sydney) Feb. 2015

Highly effective tracer of high energy particles High impact results – 18 Nature, Science, PhysRevLett papers since 2004 Great success with HESS, VERITAS, MAGIC etc. but we want & need to do more...... HESS-II, MAGIC-II, CTA

Gamma-rays (~30 GeV to ~500TeV)

http://tevcat.uchicago.edu/

TeV Milky-Way (according to HESS)

Carrigan et al 2013

TeV Milky-Way (according to HESS)

Carrigan et al 2013

Carrigan et al 2013

HESS TeV horizon 1% & 10% Crab flux > 1 TeV

Extragalactic

AGN z>0.5, GRBs, Star-bursts,

• Gal. clusters, AGN haloes..

Astro-particle

Dark matter, Lorentz invariance.... Optical Intensity Interferometry

CTA Science CTA Science

Special Issue Vol 43, Pg 1-356 (Mar 2013)

Gamma Rays from multi-TeV particles

Protons: Gamma-rays and gas targets are generally spatially correlated (need to map atomic and molecular ISM) Electrons: Gamma-ray (IC) + X-ray, radio emission (synch.) coupled (Bremss. usually minor) + CMB

Gamma Rays from multi-TeV Cosmic-Rays Gamma Rays from multi-TeV Cosmic-Rays (p, He ...etc)

(p, He ...etc)

.

p+p → πo → 2γ

π± → µ± → e± + (νµ νe ….)

GAS CLOUD Gamma-Rays (+ Neutrinos) CRs deflected by magnetic fields

Observational Signature

→ Gamma-rays and gas are ~ spatially correlated (need to measure gas in all chemical states) → Intimate connection with mm- radio astronomy (tracing gas) → Expected gamma-ray flux Fγ ~ (cosmic-ray density) x (gas mass) / (distance)2

• Energy density of galactic CRs similar to that in starlight,

magnetic fields, and gas kinetic energy → these energy densities are all tightly connected.

→ CRs carry energy throughout galaxies → CRs intimately linked to evolution of stars and galaxies

• CRs are a signpost of massive stellar evolution

– death (supernova remnants)

– life (winds from massive stars) – birth (perhaps) signalling onset of fusion/stellar winds – initiates astro-chemistry → life!

• Where do magnetic fields come? Are they important?

– Magnetic fields can greatly inflence star formation!

– CRs can create magnetic fields - they ionise atoms

• CRs and electrons trace outflows and jets

– jets, pulsar winds, accretion, GRBs-hypernovae.....

Why study cosmic-ray (CRs) and electrons?

Gamma-Rays from Cosmic-Rays escaping RXJ1713 SNR

Isotropic diffusion Casanova etal 2010 (Gabici etal 2009)

tesc ~ (E/Emax)2.3 Age = 1600 yr, d = 1 kpc Slow diffusion D = 1026 cm2/s → Expect ~degree-scale TeV emission (γesc + γdiffuse) / γdiffuse

CR propagation along B flux tube

Isotropic Anisotrpic CR overdensity

Malkov etal 2013 Nava & Gabici 2013

→ Nearby clouds will see different CR densities → Need detailed maps of ISM gas + B-field direction

CR diffusion – not necessarily Isotropic!

R = distance CR travels into molecular cloud core χ=diffusion suppression → Low energy CRs can't reach cloud core. → Expect harder TeV spectra from cores. → Don't expect electrons to penetrate!! (due to sync. losses) → Need to map dense cloud cores

CR Diffusion Into Molecular Clouds Gabici etal 2007

10 TeV proton 1 TeV proton

• mol. cloud core

• CTA will provide Galactic Plane TeV Gamma-ray maps
• n ~1-3 arc-min scales

(~0.5 arc-min possible – high quality cuts)

• >3 sources per deg2 |b|<0.2o |l|<30o (Dubus etal 2013)
• Diffuse TeV components visible?

from CR 'sea' – maybe local CR accelerator enhancements – yes Confusion guaranteed (same as for Fermi-LAT at GeV energies!)

• Mapping the ISM on arc-min scales over the plane will be essential

Mopra (CO, CS ), Nanten2 (CO), ASKAP (HI, OH), THz (CI, C+)

Galactic Plane TeV Surveys : Major Issue

Funk et al 2012

Angular Resolution (HESS, CTA..) Acharyara etal 2013

CTA – 2 tels >=10 tels ISM cloud core at few kpc Typical radius CTA MST-SCTs with small pixels and/or hi-res cuts → resolve cloud cores! X e.g. Cameron et al 2012 HESS hi-res cuts

e.g. DeNaurois etal 2009

We need to map the interstellar gas to discriminate hadronic vs. leptonic gamma-rays!

HI (atomic H), OH CO CO, NH3, CS, SiO... Gas density ~101 to 2 cm-3 ~103 cm-3 >10 3 to 4 cm-3

ATCA Parkes ASKAP

HEAT – THz telescope (Antarctica) [CI] + [CII]

→ tracing the complete C budget!

http://www.physics.adelaide.edu.au/astrophysics/MopraGam/ Team Members Gavin Rowell (lead, Adelaide), Michael Burton (UNSW), Yasuo Fukui (Nagoy), Bruce Dawson (Adelaide), Andrew Walsh (Curtin), Felix Aharonian (DIAS/MPIK), Stefan Ohm (Leicester) Adelaide PhD students: Brent Nicholas (now at DSTO), Nigel Maxted (now at Montpellier), Phoebe de Wilt, Jarryd Hawkes, Fabien Voisin, Jame Lau, Rebecca Blackwell, Stephanie Pointon (MPhil student). Targets Since 2012 observed over ~40 TeV gamma and high energy sources, > 1500 hrs. Student Projects Phoebe deWilt – ISM survey of unidentified TeV sources, TeV+HII regions Jarryd Hawkes – Outflow sources (e.g. XRBs) and magnetars Fabien Voisin – Pulsar Wind Nebulae James Lau – SNR/MC associations / G328 filament Rebecca Blackwell – CMZ Stephanie Pointon – Two bright unidentified TeV sources

Dense (>104 cm-3) Cores of W28 Molecular Clouds (Nicholas etal 2011, 2012) NH3 (1,1) , CS(1-0) NE Shocked Cloud Mass of dense core ~104 Msun → Gamma-rays from CS clumps (~<10-13 ph/cm2/s) → Detectable & maybe resolvable by CTA

Core A Core C Core B

Core C n > 104 cm-3 M ~ 50 – 100 Msun Min CR energy penetrating Core C

• vs. diffusion

supression χ → Another way to probe CRs from SNR.

RXJ1713: Dense Cores CS(1-0) (Mopra)

Maxted etal 2012 χ=10−3 χ=10−4 χ=10−5

HESS J1745-303

NH3

• rtho/para

ratio studies

HOPS

Survey of NH3, H20 masers, plus

• ther 12mm lines

Walsh etal 2011, Purcell etal 2012

Mopra HOPS++ & Unidentified TeV Sources DeWilt etal 2012,2015

http://awalsh.ivec.org/hops/public/ index.php

Where are the ions in pulsar Winds? (Fabien Voisin)

• Ions expected in pulsar winds?

e.g. Gallant & Arons 1994

• Only indirect evidence X-ray wisps

Gaensler etal 2002

→ Look at dense mol. gas

Best case: HESSJ1825-137

Voisin etal 2014 Nanten CO Mopra CS, NH3, SiO Mopra CS, H62a, NH3(1,1)

HESSJ1640-465 & HESSJ1641-463 (James Lau)

Nanten CO(1-0) Mopra CO(1-0)

ISM Studies of Magnetars (Jarryd Hawkes)

HESSJ1616-508 & HESSJ1614-518 (Stephanie Pointon)

Westerlund 1 – The Wolf-Rayet Haven

(Gavin Rowell, Stefan Ohm) >24 WR stars, ~80 blue supergiants ! Lwind ~ 1040 erg/s; Age ~ 5 Myr (Crowther etal 2006) X-rays Lx-ray ~ 1034 erg/s (Muno etal 2006) LTeV~ Lx-ray PSR J1648-4611 Pspindown ~ 1033 erg/s/kpc2 Magnetar: AXP CXOU J1647-4552

Aharonian etal 2012

Molongolo 848 MHz image

First Results from H.E.S.S. phase II First Results from H.E.S.S. phase II

Gavin Rowell (for the H.E.S.S. collaboration)

Statistics (17 hr) ~8σ signif (a-priori) Nγ = 6059 ± 640 <E> = 40 GeV First “Mono” Results from New 28metre Telescope ~30 GeV threshold

• Vela Pulsar
• Crab Nebula
• Gal. Centre
• 2 AGN

→ Improved 0.1–10 TeV sensitivity

Pulsar period - 89ms Grey Band Fermi-LAT pulsar peak phase

2008-2014 Adelaide-led 7/12mm targeting now ~ complete 3mm CO survey extensions underway TeV SNR shell surrounds (RXJ1713, VelaJnr, HESSJ1731) 2015 New targets (>~300 hr for 7/12mm?):

• LMC 30DorC etc. 3mm CO, CS, SiO
• CO survey extensions (CCC, TeV SNRs...)
• HESS 'PeVatrons'
• HESS Collaboration AO next week!
• Other suggestions welcome

Already great legacy for HESS-II and CTA 2016-2018 Mopra LIEF submit Apr 2015

• Complete CO survey b<=+-1.0deg..
• CS/NH3 survey of CTA Key Science Project regions?

MopraGam – The Next Steps

Thank you..