Supernovae and the IFU. Ryan Foley University of Illinois and Dan Scolnic University of Chicago

Transcription

1 Supernovae and the IFU Ryan Foley University of Illinois and Dan Scolnic University of Chicago

2 WFIRST-AFTA White Paper R 1 IFU Spectrograph.6 λ 2 µm 7 Epochs of IFU Spectroscopy at S/N = 3 1 Epoch Near Max at S/N = 1 1 Epoch at Late Times at S/N = 6 5-day cadence 4.2 Months for Spectroscopy No mention of selection, false positives, or if S/N is peak/median/other

3 Our Simulations Start with WFC3 IR Grism for Sensitivity Scale To Match Total Time in White Paper Assume Peak S/N Add Appropriate Noise Determine Recovery Rate ( z <.5, >8% SN Ia Match, Best Match)

4 6 5 z =.2 Relative f λ Observed Wavelength (µm)

5 6 5 z =.2 Relative f λ Observed Wavelength (µm)

6 6 5 z =.2 S/N = 3 Relative f λ Observed Wavelength (µm)

7 6 5 z =.2 S/N = 1 Relative f λ Observed Wavelength (µm)

8 6 5 z =.2 S/N = 2 Relative f λ Observed Wavelength (µm)

9 6 5 z =.2 S/N = 5 Relative f λ Observed Wavelength (µm)

10 6 5 z = 1.5 Relative f λ Observed Wavelength (µm)

11 6 5 z = 1.5 Relative f λ Observed Wavelength (µm)

12 6 5 z = 1.5 S/N = 3 Relative f λ Observed Wavelength (µm)

13 6 5 z = 1.5 S/N = 1 Relative f λ Observed Wavelength (µm)

14 6 5 z = 1.5 S/N = 2 Relative f λ Observed Wavelength (µm)

15 6 5 z = 1.5 S/N = 5 Relative f λ Observed Wavelength (µm)

16 Resolution Matters for Classification R = 5 R = 7 R = 1 R = R = 15 Fraction Recovered S/N

17 S/N REALLY Matters for Classification S/N = 5 Fraction Recovered S/N = 2 S/N = 1 S/N = Redshift

18 Contamination Potentially High 1 8 z = 1.5 S/N = 3 Relative f λ Observed Wavelength (µm)

19 Contamination Potentially High 1 8 z = 1.5 S/N = 2 Relative f λ Observed Wavelength (µm)

20 Contamination Potentially High 1 8 z = 1.5 S/N = 5 Relative f λ Observed Wavelength (µm)

21 S/N Matters for MISclassification S/N = 5 Fraction Incorrect S/N = 2 S/N = 1 S/N = Redshift

22 S/N Matters for MISclassification S/N = 5 S/N = 2 S/N = 1 S/N = 3 1. Fraction Incorrect Redshift

23 S/N REALLY Matters for Classification S/N = 5 S/N = 2 Fraction Recovered Redshift S/N = 1 S/N = 3

24 S/N REALLY Matters for Classification 1. S/N = 5 S/N = 2 S/N = 1 Fraction Recovered Redshift S/N = 3

25 Convolved with Redshift Distribution Relaxed Strict 1. Fraction Recovered S/N

26 Samples of SNe Ia have Low R V R V = 3.1 R V = R V = A V /E(B-V) AV (mag) Foley & Kasen 211

27 Optical Spectrum to Measure Velocity 1 8 High Velocity Flux + Constant 6 4 Low Velocity Rest Wavelength (Å) Silicon

28 Measure Silicon Velocity 1 8 High Velocity: ~ -13, km s -1 Flux + Constant Low Velocity: ~ -1, km s -1 Wider Lines With Higher Velocity Rest Wavelength (Å)

29 Intrinsic Color Depends on SN Velocity High Velocity Low Velocity High Velocity SNe Ia Low Velocity SNe Ia R V = 2.5 R V = R V = A V /E(B-V) AV (mag) Foley & Kasen 211

30 Large Biases from Intrinsic Color Step Function versus Constant Mean Intrinsic Color Si II velecity (1 3 km/s) Number of SN Ia Change in A V Extinction Estimate The change in the individual extinction estimates, Mandel, Foley, & Kirshner 214

31 R 1 improves recovery rate, gives more precise (less biased) distances, and allows for additional systematic tests S/N > 2 needed for robust classification Spectroscopy from Ground? Could do everything at z < 1 with dedicated 8-m telescope Distances through imaging with single high-s/n spectrum?

32 Stat (IFU only) Stat (Imaging 4 filters) Stat(Imaging 3 filters) w w a

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