slide1 l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Summary of the Multi-Messenger Astronomy Workshop PowerPoint Presentation
Download Presentation
Summary of the Multi-Messenger Astronomy Workshop

Loading in 2 Seconds...

play fullscreen
1 / 41

Summary of the Multi-Messenger Astronomy Workshop - PowerPoint PPT Presentation


  • 288 Views
  • Uploaded on

Summary of the Multi-Messenger Astronomy Workshop Garmt de Vries Les Houches, 2002 Multi-Messenger Astronomy Workshop Organisers: D. Smith & A. Barrau 2 sessions planned 2 sessions added Goal of the workshop: To dive into the wonderful world of astrophysical catalogues!

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Summary of the Multi-Messenger Astronomy Workshop' - johana


Download Now An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1

Summary

of the

Multi-Messenger Astronomy

Workshop

Garmt de Vries

Les Houches, 2002

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002

slide2

Multi-Messenger Astronomy Workshop

  • Organisers: D. Smith & A. Barrau
  • 2 sessions planned
  • 2 sessions added

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002

slide3

Goal of the workshop:

To dive into the wonderful world

of astrophysical catalogues!

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002

slide4

We play a little game:

  • Imagine a 0.1 km2 detector

with 3 years of data

resolution ~ 1o

  • After subtracting the atmospheric background

there is one bin with 7 events:

RA = 12h 34’ δ = - 56.78o

  • What can this be?

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002

slide5

Possible explanations

  • Statistical fluctuations
  • Gamma Ray Burst (GRB)
  • SuperNova (SN)
  • Pulsar, SuperNova Remnant (SNR)
  • Active Galactic Nucleus (AGN)
  • SuperSymmetry (SUSY)
  • Microquasar
  • ...............

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002

slide6

How to play the game?

  • Look in catalogues at this place
  • Look for coincidence with VIRGO, HETE, AUGER, ...
  • Look at various models
  • Which model(s) can be excluded?
  • Which model(s) explain(s) the data best?

We split up into subgroups and investigate the various hypotheses

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002

slide7

Let the game begin!

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002

slide8

Statistical fluctuations

(S. Cartwright et al.)

  • It is known from previous experience that:
  • 30 bins give a background of 3 events/year
  • expect ~ 0.3 event/bin in 3 years
  • Probability of finding 7 events in this bin: 3.2 10-8
  • Probability of finding 7 events in at least one

of the 40,000 bins: 1.3 10-3

Probably not a statistical fluctuation

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002

slide9

GRB

(S. Ferry et al.)

There are 3 GRBs close to RA = 188.5oδ = - 56.78o

in the BATSE catalogue:

4B950628 RA = 180o δ = -55.88o Error box radius:

l = 295.72o b = 6.27o 4.93o

GRB961224 RA = 182.84o δ = -64.64o Error box radius:

l = 298.66o b = -2.11o 5.4o

GRB971210 RA = 176.91o δ = -51.95o Error box radius:

l = 293.04o b = 9.69o 1.11o

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002

slide10

GRB

(continued)

  • Possible actions:
  • Send alert to SN people (GRB  SN?)
  • Try to get timing information
  • Look for γ-rays
    • If both γ and ν observed  GRB not leptonic
    • If no γ observed  choked GRB?

(look for afterglow!)

 Multi-messenger interplay is certainly possible

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002

slide11

AGN

(N. Girard et al.)

There is no quasar near RA = 188.5oδ = - 56.78o

Other types of AGN have not been looked for

Anyway, hadronic models predict ~ 100 times fewer ν events

This hypothesis can be excluded

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002

slide12

Microquasar

(S. Karkar et al.)

No microquasar was seen near RA = 188.5oδ = - 56.78o

This hypothesis can be excluded

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002

slide13

SUSY

(S. Cartwright et al.)

  • One could expect a SUSY signal from:
  • Galactic centre
  • Sun
  • Centre of the earth

None of these are close to RA = 188.5oδ = - 56.78o

 Perhaps a galactic halo clump?

One would also expect to see ~ 10 GeV γ-rays

Further investigation needed

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002

slide14

Diffuse background

(A. Romeyer et al.)

Yellow area:

4 detection possible

It seems to be difficult to get a good signal

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002

slide15

Conclusions

Our cluster of 7 events is not due to statistical fluctuations

To say more, we need further information:

Time

Energy

Other messengers

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002

slide16

Neutrino Astronomy with MACRO

This paper describes exactly the game we played

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002

slide17

Neutrino Astronomy with MACRO

Search for pointlike sources with clustering algorithm:

Look in 1.5o, 3o, 5o around each of the 1100 muon events

  • 60 clusters of  4 events found in 3o cone

RA δ # events

222.5o -72.7o 7

188.1o -48.1o 6

342.5o -74.4o 6

Compatible with atmospheric ν background

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002

slide18

Everything is compatible with atmospheric ν background

Neutrino Astronomy with MACRO

Search among known point sources:

Make a list of 42 sources that look interesting

Look in 1.5o, 3o, 5o around each of these sources

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002

slide19

Neutrino Astronomy with MACRO

MACRO observed neutrinos from the direction of

microquasar GX 339 – 4:

“We notice that there are six events from GX 339 – 4 in a 3o search cone with chance probability P = 6  10-3. Considering that we have looked at 42 sources, the probability of finding such an excess from at least one of these sources is 8.6%.”

Still, this source was interesting enough for our working group to investigate it

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002

slide20

Microquasars

(courtesy F. Mirabel)

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002

slide21

GX 339 – 4

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002

slide22

GX 339 – 4

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002

slide23

GX 339 – 4

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002

slide24

2000

Neutrinos from GX 339 – 4

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002

slide25

Neutrinos from GX 339 – 4

10/10/95

21/02/97

06/07/98

18/11/99

01/04/01

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002

slide26

The big question:

How surprising is it

to see 7 neutrinos from GX339 – 4

during and after its active period?

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002

slide27

Neutrinos from microquasars

Presentation by D. Guetta:

Predictions of neutrino fluxes from microquasars

  • GX339 – 4 is one of the most powerful neutrino sources among microquasars:

~ 200 upward going muon events per year in 1 km3

However:

This prediction is based on the assumption that GX339 – 4 is persistent. The active state has not been taken into account.

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002

slide28

Neutrinos from microquasars

There is no a priori connection between soft X-ray activity and neutrino emission

Correlation between dip in ~ 50 keV photons and neutrino emission could be understood:

Source optically thick for these γ  more γ present that can serve as a target for ν production

But the connection is not very clear...

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002

slide29

3  10-3

4  10-3

1  10-4

Statistics

What is the probability of seeing these 7 neutrinos from the direction of GX339 – 4 ?

Seeing 7 neutrinos during 7 years

Seeing 3 neutrinos during the 450 days active period

Seeing 3 neutrinos clustered in a 30 day period during 7 years

 Chance probability ~ few  10-3

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002

slide30

Statistics

We need the probability of finding 7 events from at least one of the sources considered:

Looking at all 42 sources on the MACRO list:

P  8.6  10-2

Looking only at the microquasars on the list:

P  1  10-2

Looking only at GX339 – 4 and SS433, for which a high neutrino flux is predicted:

P  6  10-3

But how valid is all this?

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002

slide31

sees nothing

GX339 – 4 is above AMANDA’s horizon

??

??

terrestrial gamma flashes?

GX339 – 4 is visible for 19.6 hrs/day

Other signals?

Super-K

AMANDA

BATSE

ANTARES

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002

slide32

No active periods!

Neutrinos from other microquasars?

A high flux is also predicted for microquasar SS433

(835 events year-1 km3)

MACRO sees no neutrinos from this sources

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002

slide33

Neutrinos from other microquasars?

A very bold assumption:

Microquasars emit neutrinos

during their active state

Microquasars emit neutrinos

during their active state

One would have to look at all the microquasars in MACRO’s field of view, and search for a correlation.

Two things may happen...

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002

slide34

Further ideas:

  • ....................................
  • ....................................
  • ....................................
  • ....................................
  • ....................................
  • ....................................
  • ....................................
  • ....................................

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002

slide35

To be continued...

Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002