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Galactic Plane Paper Update Curtis Lansdell Milagro Collaboration Meeting December 18, 2006.

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Presentation on theme: "Galactic Plane Paper Update Curtis Lansdell Milagro Collaboration Meeting December 18, 2006."— Presentation transcript:

1 Galactic Plane Paper Update Curtis Lansdell Milagro Collaboration Meeting December 18, 2006

2 Curtis Lansdell December 18, 2006 Milagro Collaboration Meeting Outline Paper outline Calculating the flux Plots for the paper Longitude & latitude profiles, significance Plots of the position fits Flux and position tables Point-like, diffuse Summary and To-do List

3 Curtis Lansdell December 18, 2006 Milagro Collaboration Meeting Paper Outline Keep it simple! Title suggestion: Milagro TeV Gamma-Ray Survey of the Galactic Plane Introduction why is this paper interesting? Analysis reference A4 weighted analysis from ApJ paper talk about steps to get a flux map in the weighted analysis mention energy response as a function of declination (i.e., why did we choose 12 TeV?) Plots and numbers significance map for the galactic plane (or entire sky?) longitude and latitude profiles (with GALPROP model - conventional, EGRET-optimized?) 4 latitude profiles: inner galaxy left of Cygnus region, inner galaxy right of Cygnus region, Cygnus region, and outer galaxy table of >4.5 sigma “point-like” blobs on the plane (include Crab): position, significance, flux table of diffuse regions: source l,b box, significance, flux, GALPROP flux inner & outer galaxy, Cygnus region (with or without hotspot and/or other blobs?), regions of inner galaxy not including Cygnus region Discussion flux compared to GALPROP is high in some regions - possible reasons GALPROP bumps compared to Milagro - line up? SNRs and PWNs in blobs Conclusion scanned the plane for new sources at >4.5 sigma level, GALPROP under-predicts, …

4 Curtis Lansdell December 18, 2006 Milagro Collaboration Meeting Flux Calculation for Weighted Analysis Simulate expected gammas per day as a function of declination with user-defined input flux and spectrum Use exposure time for each data epoch and pre-defined weights to get expected weighted events as a function of declination Scale the real data excess by expected weights to get data map in Crab flux units Sum up regions of interest, normalize with thrown flux, spectrum, and median energy of analysis, average with respect to angular size

5 Curtis Lansdell December 18, 2006 Milagro Collaboration Meeting Significance Plot Which one?

6 Curtis Lansdell December 18, 2006 Milagro Collaboration Meeting Profile Plots I Cygnus Hot Spot Cygnus Region Optimized Model Longitude Profile Latitude Profile Inner Galaxy (IG) Outer Galaxy (OG) Latitude Profile flux calculated at 12 TeV and -2.62 spectrum

7 Curtis Lansdell December 18, 2006 Milagro Collaboration Meeting Profile Plots II Latitude Profile Inner Galaxy, “below” Cygnus Region Inner Galaxy, Cygnus Region Inner Galaxy, “above” Cygnus Region

8 Curtis Lansdell December 18, 2006 Milagro Collaboration Meeting >4.5  regions 6 regions, all within inner galaxy Expect 0.3 spots >4.5  in l  [30°,120°], b  [-5°, 5°] Expect 0.6 spots >4.5  in l  [30°,216°], b  [-5°, 5°]

9 Curtis Lansdell December 18, 2006 Milagro Collaboration Meeting Crab and MGRO J2019+37 Fit performed on unsmoothed map and overlayed on smoothed excess map Green circles are 0.5  contours Purple dots are initial guesses on position (or known position in the case of the Crab (l, b) = (-175.4°, -5.8°)) Weighted events point source resolution ~0.64°

10 Curtis Lansdell December 18, 2006 Milagro Collaboration Meeting l=76.3 and l=77.5 Limited search box to 2°x2° centered at purple dot to avoid poor fits due to nearby sources For ~0.6° resolution, a bin of ~2° seems reasonable

11 Curtis Lansdell December 18, 2006 Milagro Collaboration Meeting l=80 and l=105.9 HEGRA spot is at (l, b) = (80.2°, 1.1°) More parameters in the fit (e.g., elliptical) does not give a better fit (e.g., for l=105.9,  2 /ndf = 3617/3594 and position is the same)

12 Curtis Lansdell December 18, 2006 Milagro Collaboration Meeting l=40.6 Low declination object (  ~ 6°) Possibly a flaring source (see Gary’s talk tomorrow)

13 Curtis Lansdell December 18, 2006 Milagro Collaboration Meeting Flux and Position Tables I Objectsignificance (std deviations) flux (/TeV/cm 2 /s/sr) GALPROP (/TeV/cm 2 /s/sr) position box |b|<5 IG7.3(1.46±0.20)x10 -12 6.79x10 -13 30<l<120, |b|<5 IG below Cygnus4.8(2.19±0.46)x10 -12 1.06x10 -12 30<l<65, |b|<5 IG in Cygnus8.5(2.29±0.27)x10 -12 5.94x10 -13 65<l<85, |b|<5 IG above Cygnus1.2(2.39±1.99)x10 -13 3.47x10 -13 85<l<120, |b|<5 OG1.4(2.82±1.95)x10 -13 2.02x10 -13 120<l<216, |b|<5 Objectsignificance (std deviations) flux (/TeV/cm 2 /s/sr) GALPROP (/TeV/cm 2 /s/sr) position box |b|<2 IG9.1(2.99±0.33)x10 -12 9.64x10 -13 30<l<120, |b|<2 IG below Cygnus6.6(4.87±0.74)x10 -12 1.61x10 -12 30<l<65, |b|<2 IG in Cygnus10.0(4.20±0.42)x10 -12 7.99x10 -13 65<l<85, |b|<2 IG above Cygnus1.3(4.08±3.13)x10 -13 4.17x10 -13 85<l<120, |b|<2 OG0.8(2.50±3.14)x10 -13 2.32x10 -13 120<l<216, |b|<2 Working on getting upper limits for galactic plane OG and IG above Cygnus region… flux calculated at 12 TeV and -2.62 spectrum

14 Curtis Lansdell December 18, 2006 Milagro Collaboration Meeting Flux and Position Tables II Objectflux (>12 TeV) (/cm 2 /s/sr) PRL flux (>12 TeV) (/cm 2 /s/sr) position box IG (PRL)(0.89±0.14)x10 -11 (1.02±0.21±0.32)x10 -11 40<l<100, |b|<5 OG (PRL)(2.58±1.30)x10 -12 < 5.57x10 -12 140<l<200, |b|<5 Object 1 significance (std deviations) flux (/TeV/cm 2 /s) GALPROP (/TeV/cm 2 /s) width (deg) position (l, b) Crab14.2(4.68±0.44)x10 -14 3.86x10 -16 0.64±0.05-175.4±0.1,-5.7±0.1 l=40.66.9(3.95±0.80)x10 -14 5.31x10 -15 0.61±0.1140.6±0.1, -1.0±0.1 MGRO J2019+3710.9(2.42±0.33)x10 -14 2.09x10 -15 1.00±0.1774.9±0.1, 0.4±0.2 2 l=76.35.2(7.65±2.17)x10 -15 7.28x10 -16 0.35±0.1176.3±0.1, -2.0±0.1 2 l=77.55.0(9.36±2.18)x10 -15 4.01x10 -16 0.64±0.2177.5±0.3, -4.0±0.2 l=805.8(1.67±0.33)x10 -14 2.29x10 -15 2.26±0.5380.1±0.5, 1.0±0.5 l=105.95.2(6.25±3.56)x10 -15 8.41x10 -16 0.36±0.15105.9±0.1, 3.0±0.1 “l=“ region fluxes taken from box centered at the fit position 1  Gaussian-smoothed significance, not corrected for declination (or assuming a spectrum) 2  2°x2° box used instead of 3°x3° so that fit doesn’t go crazy due to nearby hot spots

15 Curtis Lansdell December 18, 2006 Milagro Collaboration Meeting Summary and To-Do List 6 spots >4.5  in Galactic plane from l  [30°,216°], b  [-5°,5°] All 6 spots within the Inner Galaxy Total flux from the 6 spots is  (6 spots, 12 TeV) = (1.04±0.10)x10 -13 /TeV/cm 2 /s Total flux from the IG is  (IG,12 TeV) = (4.00±0.55)x10 -13 /TeV/cm 2 /s The 6 spots make up ~25% of the flux from the Inner Galaxy Get upper limits on low significance diffuse regions (OG, IG above Cygnus region) List SNRs, PWNs within these 6 spots Bumps in GALPROP match excess bumps? i.e., do any of our “source” regions match with regions of higher diffuse emission? Finish the draft! …


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