1. Gamma-rays from the quiet Sun Nicola Omodei Stanford

2. SolarTutorial Get the needed files: https://www.dropbox.com/sh/s8io1bq5yvk966j/3F6Rq3xTI4 Unpack the SolarTutorial_src.tgz and SolarTutorial_data.tgz file into the tools directory. tools/SolarTutorial should look like: –XSPEC/ (models for XSPEC) –lleBackground/ (tool for extracting the LLE background) –src/ (python code) –data/ (data, FT1, FT2 and LLE, template file for likelihood analysis, isotropic model and galactic diffuse model)

4. Direct Download -> Save File

5. > 1)Inverse Compton (IC) emission from the Sun idea and theory: Moskalenko et al. 2006, Orlando & Strong 2007, 2008 Sun is bright in gammas due to interactions of Galactic cosmic rays (CR) + 2) Solar disk emission due to interactions of CR particles with solar atmosphere model : Seckel 91, upper-limit detection: Thompson 97 First detection (EGRET): Orlando & Strong, 2008 FERMI/LAT: high statistical significance for a clear separation of the components! 2011ApJ...734..116A e- p < < radial e- γ η p γ Galactic CRs Quite Sun gamma-ray emission

6. Solar gamma-ray flux depends on CRs flux Max SA -> min CR flux Min SA -> max CR flux - SA was in its minimum during the period analyzed in the Fermi LAT paper - SA is now increasing and expected to peak around 2013 Solar Activity (SA) and Cosmic rays (CR) Solar Activity (SA) and Cosmic rays (CR)

7. 7 Counts map >100 MeV Fermi paper: LAT data selection 18 months data Analysis in Sun-centered system Zenith angle < 105° (to avoid the Earth’s emission) Galactic Plane Cut (|b|>30°) (to reduce the background) Moon-Sun angular separation >40° Avoided the brightest sources, F(>100 MeV) above 2e-7 cm-2s-1 Only a small percentage of the data survives

8. Ephemerides in a nutshell #!/usr/bin/env python import pyLikelihood as pl import os from math import * def d(x): return degrees(x) def r(x): return radians(x) def getJD(met): if met > 252460801: met-=1 # 2008 leap second if met > 157766400: met-=1 # 2005 leap second if met > 362793601: met-=1 # 2012 leap second return (pl.JulianDate.seconds(pl.JulianDate_missionStart())+met)/pl.JulianDate.secondsPerDay def _jd_from_met(met): jd = pl.JulianDate(getJD(met)) return jd def getSunPosition( met ): os.environ['TIMING_DIR']=os.path.join(os.environ['HEADAS'],"refdata") sun=pl.SolarSystem(pl.SolarSystem.SUN) return sun.direction(_jd_from_met(met)) def rotation(x,y,p): xr=r(x) yr=r(y) pr=r(p) x1= d(atan2(sin(xr)*cos(pr) + tan(yr)*sin(pr), cos(xr))) y1 = d(asin(sin(yr)*cos(pr) - cos(yr)*sin(xr)*sin(pr))) return x1,y1 def equatorial2ecliptic(ra,dec): EPS = 23.439292 # THIS IS THE OBMIQUITY AS J2000 (lon,lat)=rotation(ra,dec,EPS) if lon<0: lon+=360 return (lon,lat) Difference from USNO position: 0.0007530°./sunpos.py 376358403.0

9. Sun Centered coordinates At each instant, the rotation brings –RA,DEC -> ecliptic lon-Sun lon, ecliptic latitude. The idea is to replace the RA,DEC with the new coordinates: –FT1 file (RA,DEC) –FT2 file: (RA_ZENITH, DEC_ZENITH), (RA_SCZ,DEC_SCZ),(RA_SCX, DEC_SCX)./suncenter.py –ft1 ft1fileName./suncenter.py –ft2 ft2fileName

10. Background determination Galactic and extragalactic emission along the ecliptic 2 methods for evaluating the background: Based on data Based on simulations

11. Based on data:Fake source method A fake source follows the path of the real source but many degrees away (integrated along the ecliptic)

12. Photon density profile >100 MeV Sun Fake-Sun background

13. -Sun Data - BKG - IC - Disk + Bkg+IC 13 Good description of the background Zoom in > 500 MEV Angular distribution well fitted by both disk and IC components. Angular profiles: evidence of extended emission

14. Disk SED s.i.=-2 SED for the disk emission compared with model predictions.

15. Analysis method Model “Independent” Fit for the IC Component –IC-ring models with Pls (RINGS: 5-11-20°) –Model for Disk point-like Component –Point source modeled with a PL2 Model for background Component –spatially uniform nested rings, (RINGS 10-14-17.3-20°) spectrum from fake sun

16. IC: Results IC differential spectrum IC flux

17. Disk results Energy

18. Including the quite sun in Solar flare analysis The Sun is a faint source of gamma-rays, not detected on hour long time scale. Depending on its position, can be detected in few days. This is for Sun Center coordinates, otherwise replace with R.A. and Dec. of the Sun

19. Take at home Calculate the position of the Sun (sunpos.py) Calculate the sun-centered FT1 and FT2 (suncenter.py) For long duration flares > 6 hr you will need to work in sun centered coordinates.

20. SolarTutorial Get the needed files: https://www.dropbox.com/sh/s8io1bq5yvk966j/3F6Rq3xTI4 Unpack the SolarTutorial_src.tgz and SolarTutorial_data.tgz file into the tools directory. tools/SolarTutorial should look like: –XSPEC/ (models for XSPEC) –lleBackground/ (tool for extracting the LLE background) –src/ (python code) –data/ (data, FT1, FT2 and LLE, template file for likelihood analysis, isotropic model and galactic diffuse model)

21. What’s in there ProgressBar.py* (helper function to display a progress bar…) SFLARE110307_analysis.py* (executable, run the analysis in different TIME bins, in equatorial coordinates) SFLARE110307_analysis_SC.py* (executable run the analysis in 1 time bin, in sun-centered coordinates) analysis.py (this is the script containing the analysis steps) makeProfileLikelihood.py* (Used to draw a profile likelihood, once the analysis is finished) myscripts.py (wrapper around ST) plotSED.py* (plot the SED) setup.sh (you can use to setup your environment (ignore for now) suncenter.py* (compute the sun center ft1 and ft2 files) sunpos.py* (compute the position of the sun) xspec_cmd.tcl (example of xspec command)

22. BACKUP

23. -Uncertainty in the solar modulation of electrons close to the Sun -Force field approximation for e- spectrum modulation (Gleeson & Axford 68) Starting from the Fermi electron spectrum at 1AU, 3 MODELS with Φ 0 (1AU)=400MV, but different formulations of Φ(r): MODEL 1 and MODEL 2 assume additional modulation <1AU, MODEL 3 assumes the e- spectrum constant <1AU. LIS Modulation potential E- spectrum at r=1AU as measured by Fermi Inverse Compton models

24. 1AU At 0.3AU MODEL3 e- constant <1AU MODEL1 (400MV) MODEL2 (400MV) LIS galprop AMS 02 Fermi LIS Electron spectra for IC models

25. Quiet Solar emission: pion decay Solar disk emission due to interactions of CR particles with solar atmosphere 25 Seckel ‘91 Cascade developpement in forward direction Mirrored showers, reflected by B back to the surface NAIVE: no B NOMINAL: includes CR diffusion F(> 100MeV) = (0.22−0.65) 10 −7 cm -2 s -1 for nominal