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Standard analysis of MAGIC data with MARS V151

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Title: Standard analysis of MAGIC data with MARS V151


1
Standard analysis of MAGIC data with MARS V1-5-1
  • Daniel Mazin and Abelardo Moralejo
  • IFAE

2
Timetable of the course
Mazin (analysis)
  • Last 2 / 3 hours D. Mazin on spectral unfolding
    skymaps

3
If you are getting involved in MAGIC data
analysis
  • Subscribe to the magic_soft mailing list! (info
    on releases, problems in data, bugs)

4
Versions of MARS
  • To avoid misunderstandings since March 2005
    there are in MAGIC two versions of the analysis
    code (MARS)
  • The official one, whose CVS is maintained by IFAE
    (cvsmagic.pic.es), and which runs at La Palma and
    at the PIC data center
  • The one maintained by the Würzburg group
  • Most people inside MAGIC use the standard
    version, the one we will present in this course.

5
Analysis handbook
  • A complete guide to the standard analysis of
    MAGIC data is under preparation (better late than
    never).
  • Please download the preliminary version at
  • http//personal.ifae.es/moralejo/web/
  • analysisHandbook.pdf
  • It will be of help during the course,
    particularly for the real beginners in MARS

6
MARS V1-5-1
  • Released 20 / 02 / 2008
  • To be run under root 5.12.00g (or f)
  • First version prepared to analyze easily the
    wobble data using timing and source-dependent
    parameters
  • First version with a standard skymap utility
  • Available at CVS, or through the PIC webpage
  • http//magic.pic.es/datacenter/cvs/cvs.html

7
MAGIC data center at PIC
8
MAGIC data files
  • .raw files contain all the information of a
    triggered event (all FADC slices of all pixels,
    UTC,)
  • Three types of raw files pedestals,
    calibrations, and data (showers) file names
    contain the tags _P_, _C_ or _D_
  • Data raw files also contain interleaved
    calibration and pedestal events, to track the
    evolution of conversion factors and FADC baseline
  • Central control reports (.rep) store
    information from the different subsystems (anode
    currents, drive system, star guider).

9
MAGIC data analysis chain
7 executables one root macro
  • callisto ? phe- and arrival time in each pixel
  • merpp ? Add information from central control
  • star ? Image parameters (shape, orientation)
  • osteria ? Optimize ?/h tagging, DISP and E estim.
  • melibea ? Calculate hadronness, DISP and E
  • fluxlc ? Apply cuts, get spectrum and light curve
  • CombUnfold.C ? Unfold spectrum (limited E
    resolution)
  • celestina ? Sky maps
  • Each one takes as input the output of the
    previous one(s)

10
Auxiliary programs
  • mars now reduced to a simple event display
    (reads in callisto _Y_ outputs)
  • showplot reads in files containing status
    displays (example calibxxxx.root,
    signalxxxx.root, starxxxx.root) created (besides
    their main output) by the various executables,
    and displays summary plots for the analyzed set
    of files.

11
Input and output files
  • callistomerpp _P_.raw , _C_.raw ,
    _D_.raw ? One _Y_.root file per data run
  • star _Y_.root ? One _I_.root file per data
    run
  • osteria _I_.root (both MC and real data) ?
  • RF.root, EN.root, DispPar.root (result of
    optimizations)
  • melibea _I_.root ? One _Q_.root file per
    data run
  • fluxlc _Q_.root ? spectr_.root (spectrum
    LC)
  • CombUnfold.C spectr_.root ? just status display
    (spectrum)
  • celestina _Q_.root ? skyplot.root (sky map)
  • Status display a graphical output of all the
    executables, which is stored in a root file and
    can be re-read with the program showplot

12
How to use the executables
  • Most of the settings of the analysis are written
    inside configuration files callisto.rc, star.rc
    (text files, see Mars/ directory)
  • The rest of the options are set directly in the
    command line input and output paths,
  • --log A brief set of instructions is obtained
    by running any executable with just the option
    -h

13
Some common command line options (callisto, star,
osteria, melibea, fluxlc)
  • -v verbose level (default 5)
  • -f force overwrite of output from previous
    executions
  • -b batch execution (no graphics)
  • -q quit after execution
  • -h help
  • --logfilename.log direct text output to a
    file
  • --configxxxx.rc set configuration file
  • (run executables with -h to see all options)

14
Example star.rc file
MJStar.MImgCleanStd.CleanLevel1
10 MJStar.MImgCleanStd.CleanLevel2
5 MJStar.MImgCleanStd.CleanMethod Absolute
MJStar.MHillasCalc.IdxIsland 0 MJStar.MSrcPosCalc
.SourceRaDec 5.5755 22.01444 MJStar.CalibStargu
ider yes MJStar.UseStarguider
yes MJStar.MCalibrateStarguider.Method
Culmination MJStar.MPointingPosInterpolate.Correct
Zenith yes MJStar.MPointingPosInterpolate.Correct
Azimuth yes NOTE Lines starting with are
deactivated (BUT default value of the
corresponding setting may be anything check
documentation of class at cvs.ifae.es in case
of doubt)
15
Sequence files
  • Sequences are groups of data files which are
    analyzed together. A sequence is normally defined
    by the availability of a pedestal and a
    calibration file, and includes all _D_ files that
    follow until the next pedestal file.
  • Typically, one or few sequences contain the whole
    dataset for a source in a night.
  • A sequence file is a short text file containing
    the run numbers of all the files in the sequence.
    This is a needed input for callisto and star. See
    for instance /nfs/magic-calib00/CrabNebula/seqdata
    //seqtxt at PIC

16
Example sequence file
  • Sequence 101042
  • Night 2006-09-21
  • CalRuns 101042
  • PedRuns 101041
  • DatRuns 101043 101044 101045 101046 101047
    101048 101049 101050 101051 101052
  • The last argument of the calls to callisto, star
    and melibea is the name of such a sequence file,
    like sequence00101042.txt

17
Example of star call
  • star --ind./ --out./star_tc10_5
  • --logstar.log --config./star.rc
    sequence00101042.txt
  • First two flags set the input (contains _Y_
    files) and output directories
  • --log sets name of text file where the log of
    the execution is written
  • --config points to the configuration star.rc file

18
  • Nowadays, the first steps of the analysis
    (calibration and image parameterization) are run
    automatically in La Palma and at PIC, with our
    current understanding of the best settings for
    callisto and star
  • The analyzer should then start his work by
    downloading the star (_I_.root) files
    corresponding to the data sample he is interested
    in.

19
Where to get star files for the standard analysis
  • Available at the PIC data center (usually a few
    days after data taking - please report missing
    data!). Access through magic-ui.pic.es
  • Real data /nfs/magic/DataCenter/Analysis/
  • Star_time 6-3 phe time cleaning, timing
    parameters
  • Star_notime 10-5 phe normal cleaning, no timing
    parameters
  • star Monte Carlo files under
  • /nfs/magic-montecarlo/MonteCarlo/
  • Very important parameters to choose the right MC
  • FADC type (3 epochs Siegen, Siegen w/splitters,
    MUX)
  • Wobble / no wobble
  • Optical PSF of mirror, zenith angle (zbin),
    cleaning

20
Optical PSF evolution
http//magic.pic.es/plot.htm
21
Role of Monte Carlo simulation
  • After star, MC files are needed to proceed with
    the analysis
  • For training the methods (DISP, energy
    estimation, ?/hadron tagging) train sample
  • For estimating the efficiency of the analysis for
    gamma-rays ( collection area) test sample
  • Obviously, all the analysis steps (cuts for
    instance) must be the same as for the real data

22
Splitting of MC gamma sample
  • Obviously, the MC gamma sample used for the
    training must be independent of the one used for
    estimating collection areas
  • Therefore, we must split the MC samples into two
    equivalent ones, usually called train and
    test. This is up to the analyzer (what fraction
    of MC to dedicate to each subsample)

23
Source-dependent and source-independent analysis
  • Two approaches in the analysis of MAGIC data
    after image parameterization
  • Make use of the a priori knowledge of the
    position of the (point-like) source Dist and
    other source-dependent parameters can be used in
    the g/h separation E-estimation
  • No assumption on the source position no
    source-dependent parameter allowed, DISP used to
    estimate the direction of each event ? sky map
  • The two approaches are useful, and running them
    in paralel is recommended

24
Running osteria
  • Real data star files are used as hadrons for
    training the ?/h tagging, together with MC
    gammas. DISP and E estimation training require
    just MC gammas (the used MC files are set
    independently for each task).
  • The different optimizations can be run
    separatedly
  • osteria --rf --rfhadronin2007_I_root
    --rfgammafile Gamma_I_root
  • osteria --disp --dispgammafileGamma_I_roo
    t
  • osteria --train-enr --rfengammafileGamma_
    I_root
  • Check and try the runosteriacsh scripts provided
    for the course together with the example data set
  • magic-ui.pic.es/nfs/magic-buffer00/BenasqueSchoo
    l

25
Cuts prior to training
  • Some basic cuts can be set in osteria.rc
  • SkipNonShowers sparks, minimum SIZE
  • FilterCuts leakage, of core pixels, number of
    islands
  • Note that cut expressions in osteria.rc define
    the events to be rejected
  • Beware for wobble data, do not make cuts in
    parameters which are source-dependent (contained
    in MHillasSrc)
  • Cuts will be automatically passed down the
    analysis chain. Filter cuts can be modified in
    melibea (only for test purposes!)

26
Example runosteria.csh
  • MARSSYS/osteria -f -q \
  • --configMARSSYS/osteria.rc \
  • --rfhadronin./OFF/200root" \
  • --rf --rfgammafile./MC/train/Gammaroot" \
  • --rfout. --ntrees100 --zdmax30. \
  • --log./osteria.log

Trains Random Forest for gamma/hadron separation
(--rf) growing 100 trees. With the default
osteria.rc file, both the source-dependent and
source-independent approach are trained.
27
Setting ?/h separation and energy estimation
parameters in osteria.rc. Source-dependent
  • OsteriaLoop.MRFGHSeparation.RFGHSeparationMatrix.C
    olumn0 log10(MHillas.fSize)
  • OsteriaLoop.MRFGHSeparation.RFGHSeparationMatrix.C
    olumn1 2.55floor(MPointingPos.fZd/5)
  • OsteriaLoop.MRFGHSeparation.RFGHSeparationMatrix.C
    olumn2 MHillas.fWidth
  • OsteriaLoop.MRFGHSeparation.RFGHSeparationMatrix.C
    olumn3 MHillas.fLength
  • OsteriaLoop.MRFGHSeparation.RFGHSeparationMatrix.C
    olumn4 log10(MHillas.fSize/(MHillas.fWidthMHilla
    s.fLength))
  • OsteriaLoop.MRFGHSeparation.RFGHSeparationMatrix.C
    olumn5 MNewImagePar.fConc
  • OsteriaLoop.MRFGHSeparation.RFGHSeparationMatrix.C
    olumn6 MHillasSrc.fDist
  • OsteriaLoop.MRFGHSeparation.RFGHSeparationMatrix.C
    olumn7 MHillasExt.fM3Longsgn(MHillasSrc.fCosDelt
    aAlpha)
  • OsteriaLoop.MRFGHSeparation.RFGHSeparationMatrix.C
    olumn8 MHillasTime.fRMSTime
  • OsteriaLoop.MRFGHSeparation.RFGHSeparationMatrix.C
    olumn9 MHillasTimeFit.fP1Grad
  • sgn(MHillasSrc.fCosDeltaAlpha)
  • OsteriaLoop.MRFEnergyEst.RFEnergyEstMatrix.Column0
    log10(MHillas.fSize)
  • OsteriaLoop.MRFEnergyEst.RFEnergyEstMatrix.Column1
    MHillasSrc.fDist
  • OsteriaLoop.MRFEnergyEst.RFEnergyEstMatrix.Column2
    MHillas.fWidth
  • OsteriaLoop.MRFEnergyEst.RFEnergyEstMatrix.Column3
    MHillas.fLength
  • . (5 more parameters)
  • OsteriaLoop.MRFEnergyEst.RFEnergyEstMatrix.Column9
    MMcEvt.fEnergy
  • Column numbering must start from 0 and numbers
    must be consecutive. For energy training, last
    column is the true MC energy

28
Setting ?/h separation and energy estimation
parameters in osteria.rc. Source-independent
  • OsteriaLoop.MRFGHSeparationSrcIndep.RFGHSeparation
    Matrix.Column0 log10(MHillas.fSize)
  • OsteriaLoop.MRFGHSeparationSrcIndep.RFGHSeparation
    Matrix.Column1 2.55floor(MPointingPos.fZd/5)
  • OsteriaLoop.MRFGHSeparationSrcIndep.RFGHSeparation
    Matrix.Column2 log10(MHillas.fSize/(MHillas.fWidt
    hMHillas.fLength))
  • OsteriaLoop.MRFGHSeparationSrcIndep.RFGHSeparation
    Matrix.Column3 MHillas.fWidth
  • OsteriaLoop.MRFGHSeparationSrcIndep.RFGHSeparation
    Matrix.Column4 MHillas.fLength
  • OsteriaLoop.MRFGHSeparationSrcIndep.RFGHSeparation
    Matrix.Column5 MNewImagePar.fConc
  • OsteriaLoop.MRFGHSeparationSrcIndep.RFGHSeparation
    Matrix.Column6 MHillasTime.fRMSTime
  • OsteriaLoop.MRFEnergyEstSrcIndep.RFEnergyEstMatrix
    .Column0 log10(MHillas.fSize)
  • OsteriaLoop.MRFEnergyEstSrcIndep.RFEnergyEstMatrix
    .Column1 MHillas.fWidth
  • OsteriaLoop.MRFEnergyEstSrcIndep.RFEnergyEstMatrix
    .Column2 MHillas.fLength
  • OsteriaLoop.MRFEnergyEstSrcIndep.RFEnergyEstMatrix
    .Column3
  • log10(MHillas.fSize/(MHillas.fLengthMHillas.fWidt
    h))
  • OsteriaLoop.MRFEnergyEstSrcIndep.RFEnergyEstMatrix
    .Column4 MNewImagePar.fConc
  • OsteriaLoop.MRFEnergyEstSrcIndep.RFEnergyEstMatrix
    .Column5 MNewImagePar.fLeakage1
  • OsteriaLoop.MRFEnergyEstSrcIndep.RFEnergyEstMatrix
    .Column6 MPointingPos.fZd
  • OsteriaLoop.MRFEnergyEstSrcIndep.RFEnergyEstMatrix
    .Column7 MMcEvt.fEnergy

29
Output of osteria
  • Files containing Random forests
  • RF.root
  • RFSrcIndep.root
  • Besides the random forests, these files contain
    the status displays of the osteria execution can
    be opened using showplot

30
showplot RF.root
31
c.o.g. (wobble data)
  • MC gamma mostly on a ring around the simulated
    source location
  • Hadrons (real data) inhomogeneities

32
Training hadron sample
  • Note usually we can take as training hadron
    sample the same data (ON or wobble) we want to
    analyze. When dealing with a strong source (like
    Crab), due to the gamma content of the data, some
    improvement in performance may result from using
    other data for the training, containing no gamma
    source.
  • Of the hadron events provided to osteria
    through --rfhadronin , only a small subsample
    (amounting to as many events as MC gamma events)
    is used. It is selected automatically (and by
    default) when running osteria, such that its
    overall SIZE and zenith angle distributions
    matches the ones of gammas.

33
z.a. versus log10(Size) before training hadron
selection (in the Events vs. z.a. vs. Size tab)
34
z.a. versus log10(Size) after training hadron
selection
Aim avoid that RF uses SIZE or z.a. directly as
a ?/h discriminators (they are useful as scaling
parameters, on which others depend, but in
themselves are not a good discriminators)
35
Importance of RF parameters
  • Note relevance of parameter depends on Size
    range for Sizegt80 phe- (this case) Dist is
    strongest. At higher Sizes W, L,
  • This plot very useful to detect possible
    mistakees in the selection of the MC (if a
    parameter is too good!)

36
Fast check of g/h separation (source-dep)
  • OsteriaLoop.MRFGHSeparation.TrainRatio 0.95
  • OsteriaLoop.MRFEnergyEst.TrainRatio 0.95 (in
    osteria.rc)

37
Hadronness vs. Size (source-dep)
hadrons
?
38
Source-independent ?/h separation
  • showplot RFSrcIndep.root

Note head-tail assymetry separation inside DISP
method!
39
Example runosteria_EandDisp.csh
  • MARSSYS/osteria -f -q \
  • --configMARSSYS/osteria.rc --zdmax30. \
  • --train-enr --rfengammafile./MC/train/Gammaroot
    " \
  • --rfout. --ntrees50 \
  • --disp --dispgammafile./MC/train/Gammaroot" \
  • --dispout./ \
  • --log./osteria_EandDisp.log

Trains Random Forest for energy estimation
(--train-enr) growing 50 trees. With the default
osteria.rc file, both the source-dependent and
source-independent approaches are trained. DISP
method is also optimized (--disp)
40
Output of osteria (E and DISP optimization)
  • Files containing energy Random forests
  • EN.root
  • ENSrcIndep.root
  • File containing DISP parametrization
  • DispPar.root
  • Each of them contains a (rather incomplete)
    status display

41
DispPar.root
  • gamma-PSF transversal and longitudinal (along
    image axis)

42
DispPar.root (leakage)
  • gamma-PSF transversal and longitudinal (along
    image axis)

43
EN.root, ENSrcIndep.root
  • Only plot Etrue vs. Eest
  • Source-dep approach clearly better

44
melibea
  • melibea just applies to the _I_ files the same
    cuts used in osteria for the training, and then
    calculates the estimated energy and the
    hadronness (and DISP for the source-independent
    analysis)
  • Source-dependent approach using the RF.root and
    EN.root outputs of osteria).
  • Source-independent approach using
    RFSrcIndep.root, ENSrcIndep.root, DispPar.root
  • The melibea output is one _Q_ file per _I_
    file, plus a melibea.root status display

45
melibea.rc
  • For standard analysis you can use an empty file
    as melibea.rc (check the one in
    BenasqueSchool/rcFiles). In this way, the cuts
    used for training will be automatically applied
    by melibea (Size, sparks, ).

46
Example runmelibea.csh(source-dep analysis)
  • MARSSYS/melibea -q -f \
  • --config./rcFiles/melibea.rc \
  • --ind./Crab --out./Crab/melibea \
  • --srcCrabNebula --rf --rftree./RF.root \
  • --calc-enr --rfentree./EN.root \
  • --UseDefaultSourceRADec --NOffWobble3 \
  • --log./Crab/melibea/melibea.log

47
Example runmelibea.csh
  • --srcCrabNebula process CrabNebularoot star
    files
  • --rf --rftree./RF.root calculate hadroness
    using the random forest in RF.root
  • --calc-enr --rfentree./EN.root calculate
    estimated energy using the random forest in
    EN.root
  • For wobble mode only
  • --UseDefaultSourceRADec --NOffWobble3
    re-calculate MHillasSrc, hadronness and energy
    (all source-dep) with respect to 3 Off
    positions on the camera

48
Besides, with --NOffWobble3
  • The melibea (_Q_.root) files have the same
    contents of their progenitor star files (for the
    events surviving cuts), plus
  • Mhadronness.fHadronness
  • MEnergyEst.fEnergy
  • MHadronness180.fHadronness, MEnergyEst180.fEnergy,
  • MHillasSrc180.
  • MHadronness090.fHadronness, MEnergyEst090.fEnergy,
  • MHillasSrc090.
  • MHadronness270.fHadronness, MEnergyEst270.fEnergy,
  • MHillasSrc270.
  • Note option --NOffWobble re-defined since Mars
    V1-5-0!

49
Source-dependent wobble data analysis (Mars gt
V1-5-0)
090
MHillasSrc090.fAlpha MEnergyEst090.fEnergy MHadron
ness090.fHadronness
MHillasSrc.fAlpha MEnergyEst.fEnergy MHadronness.f
Hadronness
source
Camera center
180
MHillasSrc180.fAlpha MEnergyEst180.fEnergy MHadron
ness180.fHadronness
MHillasSrc270.fAlpha MEnergyEst270.fEnergy MHadron
ness270.fHadronness
270
50
Running melibea on MC example runmelibea_MC.csh
  • MARSSYS/melibea -mc -q -f --config./rcFiles/meli
    bea.rc \
  • --ind./MC/test \
  • --out./MC/test/melibea/ \
  • --srcGamma --rf --rftree./RF.root \
  • --calc-enr --rfentree./EN.root \
  • --NOffWobble3 \
  • --log./MC/test/melibea/melibea.log
  • One must use the same RF.root, and EN.root as for
    the real data. The MC files to be melibeated are
    the test files, that is, they must be
    independent of those used for the trainings in
    melibea.

51
Some exercises on the melibea files (mainly for
beginners)
  • Using roots TChain on the Events tree (see some
    hints on how to use it in the analysis handbook
    draft)
  • Make some Alpha plots with tentative Size /
    hadronness cuts, for the on and (overlaid) for
    the wobble offs
  • Do the same for theta2 plots (using the _Q_ files
    with DISP, and the coordinates of the source
    position on the camera)
  • With the MC melibea files, check what fraction of
    the signal may end up in the off at low Alpha,
    after the hadronness cut (for the 3 off positions)

52
melibea.root file
  • This is an additional output of melibea
    containing a status display
  • Main contents
  • Histograms of various parameters (in MHillas,
    MHillasExt, MHillasSrc)
  • Plots of efficiency of prior cuts (Size, zenith
    angle, sparks) vs. Time (both overall and in
    Size bins) this may be helpful to find bad runs
    (for this purpose, check also the starroot files
    which contain the status display of star).

53
Energy spectrum and light curve
  • At this point we must have a set of real data
    melibea files , i.e. 2007_Q_.root, and a set of
    gamma MC melibea files, i.e. Gamma_Q_.root
  • Now we have to run fluxlc. Everything in fluxlc
    is configured via fluxlc.rc, then command line is
    just
  • fluxlc --configfluxlc.rc --logflux.log
  • Check MARSSYS/fluxlc.rc

54
fluxlc.rc
  • Main things to be defined
  • paths to files, output filename
  • Number of z.a. bins (for now, choose 1) and z.a.
    range.
  • Number of bins in energy (and E range)
  • Wobble / no wobble
  • Alpha (source-dep) or Theta2 (source-indep)
    analysis
  • Set hadronness and Theta2 (or alpha) cuts
  • Timescale of lightcurve (hours, days)

55
fluxlc.rc
  • Setting the files to be used, and the output file
    name
  • FluxLC.mcdata ../MC/test/melibea/Gamma_Q_.root
  • FluxLC.data ../Crab/melibea/200_Q_.root
  • FluxLC.offdata (only for on/off observations)
  • FluxLC.outname spectr_calc_out_Crab.root
  • Zenith angle range
  • FluxLC.zabins 1 (do not change)
  • FluxLC.za_edges 0., 29.

56
fluxlc.rc
  • Setting additional cuts (beyond those applied by
    osteria/melibea) if needed
  • FluxLC.UserCuts (MNewImagePar.fLeakage1lt0.2)
    (MImagePar.fNumIslandslt2)
  • Note no source-dep parameters in wobble data! A
    harder leakage cut, or various other cuts may be
    useful cut to test the stability of features in
    the spectrum or light curve.
  • FluxLC.MaxDist 1.2(x-2.5)0.2
  • Will be applied for each off position in wobble
    data, in order not to break symmetry. x stands
    for log10(Size). We can also set a fixed maximum
    Dist.
  • FluxLC.MinSize 60 (phe)

57
fluxlc.rc
  • Setting some binnings
  • FluxLC.nBinsEnergyEst 30
  • FluxLC.lowerEest 5.
  • FluxLC.upperEest 50000.
  • Data type
  • FluxLC.WobbleData TRUE
  • Type of analysis
  • FluxLC.AngleType Alpha (source-dep analysis)
  • FluxLC.AngleType Theta2 (source-indep analysis)

58
How to choose the hadronness and Alpha (or ?2)
cuts?
  • A compromise is needed between statistical errors
    and systematic errors
  • Too loose cuts bad BG discrimination, poor
    significance ? large error bars in spectrum
  • Too tight cuts statistical significance may be
    good, but at the expense of introducing a larger
    systematic error in the collection area due to
    the possible differences between the MC gammas
    and the real ones. Tight cuts will keep only
    those real events which are most similar to the
    MC

59
Two ways of setting hadronness and Alpha cuts
  • FluxLC.FindCutsFromEfficiency TRUE
  • FluxLC.AlphaEffi 0.8
  • FluxLC.HadEffi 0.5
  • The program will try to set cuts such that the
    requested efficiency is reached in each bin of
    Size. There are minimum allowed values in
    current Mars minimum values of the cuts are set
    by default at 8 degree and 0.01
  • FluxLC.FindCutsFromEfficiency FALSE
  • FluxLC.had 0.2, 0.2, 0.2, (hadronness cut)
  • FluxLC.alp 8.,8.,8., (Alpha or theta2 cut)
  • ? Cuts set manually one by one in each of the
    bins of estimated energy

60
Wobble data how many off regions?
  • FluxLC.NumberOfWobbleOff 1
  • Using just the antisource (1) is the safest
    choice to ensure an unbiased background
  • FluxLC.NumberOfWobbleOff 3
  • The statistical error in the determination of
    background will be smaller (3? statistics) , but
    the two additional Off positions are not totally
    equivalent to the source position (possible
    systematics due to camera inhomogeneities!).
    Still, it should be safe above 200 GeV

61
Background normalization
  • Wobble use just the geometrical factor
    (possible gamma contamination in the OFF)
  • FluxLC.WobGeomNorm TRUE
  • FluxLC.WobLCGeomNorm TRUE
  • (1/1) or (1/3)
  • No wobble normalization by comparing on and off
    out of the signal region. Two alternatives
  • FluxLC.CommonNormFactor TRUE
  • all energy bins have the same norm. factor
  • FluxLC.CommonNormFactor FALSE
  • each energy bin is normalized independently

62
Light curve settings
  • FluxLC.Lightcurve TRUE
  • FluxLC.LowELC 300. (GeV)
  • FluxLC.UpELC 50000. (GeV)
  • FluxLC.AutotimeBinningLC TRUE
  • FluxLC.LCTimeScale 10.
  • (min) The program wiill try to do bins in time of
    such duration
  • FluxLC.AlphaCutForLC 8.
  • FluxLC.Theta2CutForLC 0.04
  • FluxLC.TimeFormat HMS (or dmy, MJD)

63
Calculation of collection areas
  • Obtained from MC in fine bins of zenith angle and
    energy, then weighted according to the z.a.
    distribution of the data, and to an assumed
    energy distribution (default -2.6 spectral index)
    in order to obtain the coll. Area in the coarse
    bins (E and z.a.) of the analysis
  • For the spectrum unfolding done later by the
    program following fluxlc
  • For the light curve since V1-5-0, a sort of
    spillover correction is applied to account for
    the finite energy resolution.

64
Recommendations for running fluxlc
  • Managing to obtain a spectrum does not mean it is
    the correct one
  • Always try to apply your analysis (RF, energy
    est) to the Crab, from data as similar as
    possible (PSF, z.a., FADC type) to those you are
    interested in. Check the obtained Crab spectrum
    before the one of your source.
  • Try different cut strengths (Alpha, hadronness).
    In this way you can estimate the possible
    systematics due mismatches of MC and data ? grey
    band in spectrum

65
Recommendations for running fluxlc (II)
  • Managing to obtain a spectrum does not mean it is
    the correct one
  • In wobble, check whether or not the spectrum
    changes significantly by using just 1 off
    (antisource) w.r.t. using, for instance, 3.
  • In any case, check always the individual Alpha or
    ?2 plots to look for background estimation
    problems

66
Output of fluxlc
User-selected maximum Dist
  • spectr_calc_.root ? input for unfolding
  • Status_spectr_calc_-root ? status display

67
Cut efficiency vs. Eest
  • Note do not expect exactly the requested
    efficiencies in the case FindCutsFromEfficiency
    TRUE. Those are in Size bins, and there are
    minimum allowed values of the cuts

68
Rate vs. Zenith angle
69
Collection area in fine bins
70
Coll. Area in coarse bins (for spectrum)
71
Overall Alpha distribution
72
Differential energy spectrum
  • Not yet unfolded
  • Automatic upper limits calculation not yet
    introduced (? introduce Mrolke here?)

73
Coll. Area for light curve
74
Light curve
  • BG also shown to identify possible trends

75
Running fluxlc
  • Edit the fluxlc.rc file (from MARSSYS for
    instance)
  • Set the correct input files for your sample
  • (optional) set a MinSize cut of 150phel to speed
    up execution
  • Prepare several copies of that fluxlc.rc, with
    different values of cut strengths, with/without
    maximum Dist cut, with 1 or 3 wobble Offs Take
    care to name the output files differently
  • Run these to use their outputs for the unfolding
    tomorrow.
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