Multi-Channel Astrophysics & Cosmology

at the Highest Energies

Vasiliki PavlidouUniversity of Chicago

Vasiliki Pavlidou Ultra high energy photons, protons and neutrinos Penn State, May 17

Outline

o The need for multi-channel studies in High-Energy Astrophysics

o The next 10 years of High-Energy Messengerso What to look forward to:

Breaking the degeneracy: AGNs, SNRs, GRBs, UHECRs Serendipitous discoveries Astrophysics with high-energy observations:

measuring cosmic star formation

Vasiliki Pavlidou Ultra high energy photons, protons and neutrinos Penn State, May 17

Why multi-channel and multi-wavelenght?

Vasiliki Pavlidou Ultra high energy photons, protons and neutrinos Penn State, May 17

Multi-channel and multi-wavelength studies:

a must for high-energy astrophysics

o Tested and tried: low energy photons + high energy observationsor GeV + TeV photons source identifications

(GRBs, gamma-ray loud blazars, pulsars, PWN) better monitoring of system variability, local

conditions large spectral dynamical range, better tests for

emission models Pian, Vacant, Tagliaferri, Ghisellini, Maraschi, Treves, Urry, Fiore, Giommi, Palazzi, Chiappetti, & Samburna 1998

Markarian 501

Reimer & Funk 2006

NRAO 530 / 2EG 1735-1312

Bower, Backer, Wright, Forster, Aller, & Aller 1997

Vasiliki Pavlidou Ultra high energy photons, protons and neutrinos Penn State, May 17

High-Energy observations in the Next Decade

o GLAST: continuous full-sky coverage in GeV gamma rays

o Ground-based TeV telescopes: (CTA/AGIS/HAWC):full sky accessible in TeV gamma rays, high angular resolution

o IceCube, KM3NeT: continuous full-sky coverage in TeV neutrinos

o Auger South + North: continuous full-sky coverage in UHE CRs, photons, neutrinos

o Perks: LIGO, LISA, JWST

Vasiliki Pavlidou Ultra high energy photons, protons and neutrinos Penn State, May 17

The future: 1. Breaking the degeneracy

o What is the origin of cosmic rays?o AGNs, SNRs: hadronic or leptonic processes?o AGNs, leptonic emission: SSC or EC?o AGNs, GRBs: how high do they go? (GLAST,

CTs, UHECRs)o What is making the highest energy particles?

Top-down or bottom up? UHECRs, GLAST

A success story from cosmology

Vasiliki Pavlidou Ultra high energy photons, protons and neutrinos Penn State, May 17

The future: 2. Serendipitous discoveries

o XXX2017: winning the jackpotnearby transient (merger between compact objects ?) GLAST detects it as a very bright transient gamma-ray

source. Follow up with Cherenkov detectors - high angular

resolution. LIGO detects gravitational wave emission; nature of

progenitor known at high confidence Low-energy multi-wavelength campaign Neutrino detectors pick up the -spike Auger picks up the UHE particle signature (time broadening

small and understood!)

A success story from neutrino astrophysics

Vasiliki Pavlidou Ultra high energy photons, protons and neutrinos Penn State, May 17

The future: 3. Low-E astrophysics with high-E observations

o The Cosmic Star Formation Rate: how much gas mass is converted to stars per unit time per unit cosmic volume

o An essential measure of: baryonic energy production, feedback processes in structure formation

o Contributes to reionizationo Links all of the messengers of interest!o Traditional measures: SF makes stars - young

stars emit in UV, IRcompilation by Hopkins & Beacom 2006

Vasiliki Pavlidou Ultra high energy photons, protons and neutrinos Penn State, May 17

The SF - high-energy connection

o Star Formation -> Supernovae -> Cosmic ray acceleration -> interaction with ISM -> ,

o Star Formation -> gamma-ray bursts -> UHECRs?, ,

o Star Formation -> Background starlight (EBL) -> interaction with: , UHECR EBL imprinted on spectra of: individual -ray sources, -ray

background, UHECRs Cosmogenic ,

Blain & Natarajan 2000Starforming galaxies (VP & Fields 2002)Unidentified sources (VP, Siegal-Gaskins, Fields, Olinto & Brown 2007)Blazars (VP & Venters 2007)EGRET gamma-ray background, conservative (Strong et al 2004)Maximal EGRET gamma-ray background (Sreekumar et al 1998)

Stecker 1999

Kalashev, Semikoz & Sigl 2007

Allard, Ave, Busca, Malkan, Olinto, Parizot, Stecker & Yamamoto 2006

Vasiliki Pavlidou Ultra high energy photons, protons and neutrinos Penn State, May 17

How do we utilize this connection?

o Until now: use knowledge of CSFR to predict signal/effects for high-energy telescopes

o The future: concurrent high-E observations in different channels allow inversion of the problem: use observations of high-E signal/effects to constrain CSFR

o Uncertainties: significant, BUT largely uncorrelated with uncertainties of low-E methods

Strigari, Beacom, Walker & Zhang 2005

Vasiliki Pavlidou Ultra high energy photons, protons and neutrinos Penn State, May 17

CSFR teaser: 15 yrs from now

o GLAST has detected: CSFR peak in gamma-ray background @E ≈ 1 GeV pileup/suppression of gamma-ray background @ E20GeV unabsorbed spectra of hundreds of low-z blazars

o GLAST+Cerenkov Telescopes have detected: EBL absorption signatures in high-E tail of

hundreds/thousands of high-z blazar spectrao IceCube/KM3NeT have detected:

Cosmogenic neutrino signatureo Auger has determined:

Spectrum, composition, sources and their cosmological evolution, acceleration mechanism of UHECRs,

Exact shape of GZK

Prodanovic, VP & Fields preliminary

+ improved IR CSFR observations by Spitzer, JWST+ good sampling of GRB afterglows, strong constraints of z-distribution of GRBs

Vasiliki Pavlidou Ultra high energy photons, protons and neutrinos Penn State, May 17

Conclusions

o Multi-channel, multi-wavelength observations give unique new insight into high-E astro

o The time to do high-energy astrophysics is now: Combined data from different upcoming instruments

+ improved low-E observations => unprecedented possibilities for: multi-channel, multi-wavelength monitoring of the high-E sky, resolution of model degeneracies

A new era: high-E observations can quantitatively map the cosmic history of baryonic energy generation and feedback