Type Ia Supernovae from Near-IR Photometry

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1 Type Ia Supernovae from Near-IR Photometry Kevin Krisciunas, Mark Phillips, Nick Suntzeff LasCampanasand Cerro Tololo Observatories References: Krisciunas et al (astro-ph/ ) Krisciunas et al (astro-ph/ )

2 IR Light Curves of SNe Ia: In the Beginning there was Elias et al. B max B max BV R V I V J H K From: Elias et al. 1985

3 The First H-band Hubble Diagram for SNe Ia: The data suggest a dispersion of 0.2 mag From: Elias et al. 1985

4 SN 1986G: The first clear evidence that not all SNe Ia are identical From: Frogel et al. 1987

5 SN 1998bu: The first SN Ia to be observed before maximum light in the near-ir The maxima in JHK occur ~5 days before B max From: Hernandez et al. 2000

6 Meikle (2000): The first study of the near-ir absolute magnitudes of SNe Ia

7 Is the slope of the luminosity vs. decline rate relation in the near-ir less steep than in the optical?? From: Meikle 2000

8 The LCO/CTIO IR Supernova Program Goals To characterize the JHK light curves of SNe of all types To derive bolometric light curves to better understand the physics of SN explosions To produce Hubble diagrams in JHK for SNe Ia To avoid the effects of host galaxy dust reddening, while at the same time validating methods for deriving the reddening from optical observations To test the extragalactic distance scale through the derivation of Baade-Wesselink distances to SNe II based on near-ir colors

9 The LCO/CTIO IR Supernova Program Goals To characterize the JHK light curves of SNe of all types To derive bolometric light curves to better understand the physics of SN explosions To produce Hubble diagrams in JHK for SNe Ia To avoid the effects of host galaxy dust reddening, while at the same time validating methods for deriving the reddening from optical observations To test the extragalactic distance scale through the derivation of Baade-Wesselink distances to SNe II based on near-ir colors

10 Campaigns to obtain JHK imaging of SNe at Las Campanas Observtory: March-May 1999 (4 Ia, 2 II) October-November 1999 (3 Ia, 1 Ic, 2 II) April-May 2000 (4 Ia, 2 II) April-June 2001 (4 Ia, 1 Ic, 2 II) 25 SNe observed: 15 Ia, 8 II, 2 Ic

11 JHK imaging of SNe at CTIO with the YALO telescope: ~10 SNe Ia observed in A few SNe II also observed Program is ongoing, with several more SNe Ia observed but not fully reduced yet Light curves extremely well-sampled due to queue scheduling of the observations

12 Examples of SNe Ia observed at LCO SN 1999ac Phillips et al (in preparation) Strolger et al (2002)

13 More examples of SNe Ia observed at LCO Krisciunas et al (in preparation) Krisciunas et al (2004)

14 Examples of SNe Ia observed with YALO Krisciunas et al (in preparation)

15 Another example of a SN Ia observed with YALO SN 2001el Krisciunas et al (in preparation) Krisciunas et al (2003)

16 S Corrections: Trying to get photometry from different telescopes to agree Not quite there yet

17 I Y J H K Optical/Near-IR Spectral Evolution of the Type Ia SN 1999ee From: Hamuy et al. 2002

18 Deriving Peak Magnitudes in the Near-IR rms=0.062 rms=0.080 The stretch method works surprisingly well for fitting the region around maximum light in the near-ir rms=0.075 From: Krisciunas et al (2004)

19 Comparing the Color Evolution of SNe Ia in the Near-IR The visual-ir color evolution of SNe Ia is similar, but not identical From: Krisciunas et al (2004)

20 Deriving the V-IR Color Excess from the Observed Magnitudes at Maximum Eventually, this method should provide the most precise determinations of the host galaxy reddening of SNe Ia From: Krisciunas et al (2004)

21 The Luminosity vs. Decline Rate Relations in BVIJHK The relations are nearly flat in the near-ir. SNe Ia are essentially perfect standard candles at these wavelengths!

22 Hubble Diagrams in the Near-IR for 21 SNe Ia rms=0.14 rms=0.18 The dispersion in the near-ir Hubble diagrams of SNe Ia is ~0.15 mag (equivalent to ±7% in distance!) rms=0.12 Krisciunas et al (in preparation)

23 Conclusions: SNe Ia are excellent standard candles in the near-ir Both optical and near-ir data for SNe Ia are consistent with a Hubble constant of Optical-IR colors should eventually prove to be the best method for determining host galaxy reddenings of SNe Ia Need more data: Stay tuned for the CSP! * * The Carnegie Supernova Program

24 Carnegie Supernova Program (CSP) (Funded by the National Science Foundation grant AST ) People: R. Carlberg, A. Filippenko, G. Folatelli, W. Freedman, S. Gonzalez, M. Hamuy, W. Krzeminski, W. Li, J. Maza, N. Morrell, D. Murphy, M. Phillips, G. Oemler, E. Persson, P. Pinto, M. Roth, S. Shectman, N. Suntzeff Institutions: Carnegie/Las Campanas Observatories Cerro Tololo Inter-American Observatory University of California at Berkeley University of Chile The University of Arizona

25 CSP Goals During the next 5 years we want to obtain high-quality gapfree optical/nir light-curves and spectro-photometry of: >100 nearby (z<0.07) Type Ia supernovae >100 nearby (z<0.05) Type II supernovae >20 nearby (z<0.05) Type Ibc supernovae with the purpose to: Establish and refine methods for obtaining distances (study of local galaxy flows, a reddening-free determination of the Hubble constant, provide a fundamental reference for observations of high-z supernovae to solve for w, w?) Gain insight into the progenitors and explosion mechanisms of supernovae

26 CSP: Implementation (Follow-up) Optical (u BVg r i ) Photometry: Las Campanas Swope 1-m telescope + CCD (151 nights) Infrared (YJsHKs) Photometry: Las Campanas Swope 1-m telescope + RetroCam (YJsH) (151 nights) Las Campanas du Pont 2.5-m telescope + WIRC (YJsHKs) (34 nights) Optical ( µm) Spectroscopy: Las Campanas du Pont 2.5-m telescope + WFCCD (or Modspec) (15 nights) Magellan + LDSS2 (or B&C and IMACS) NEED TELESCOPE PROPOSAL One 9-month campaign per year Swope 1-m Du Pont 2.5-m Magellan 6.5-m

27 Rest System I-band Photometry of High-Z SNe Ia Collaborators: Carnegie W. Freedman, E. Persson, M. Roth, B. Madore, P. Wyatt, N. Morrell CTIO N.Suntzeff

28 At z ~ 0.5, the J-band corresponds closely to the rest system I-band

29 The stretch method also works well for determining maximumlight magnitudes in the I-band. Reddening in the I-band is a factor of ~2 times less than in the B-band From: Krisciunas et al (2004)

30 Goals of the project: Observe z ~ SNe Ia discovered by the ESSENCE and CFHT Legacy programs in the Y and J bands Obtain maximum-light magnitudes through fits to a stretch template Derive the I-band Hubble diagram to verify rest system BV results for high-z SNe Ia Provide constraints on the value of w Project began in season

31 J-band image of Type Ia Supernova at z = 0.55 Baade 6.5-m Telescope PANIC IR Imager Exposure time = 36 min Seeing = 0.45 arcsec Image Credit: Wendy Freedman, Eric Persson, Pamela Wyatt (Carnegie)

32 Stay tuned

33 Collaborators: Carnegie - M. Phillips, M. Roth, S. Gonzalez, E. Persson CTIO N.Suntzeff, K. Krisciunas, P. Candia ESO - L. Germany

34 Outline of Talk: A bit of history The LCO/CTIO IR Supernova Program Absolute magnitudes & Reddening Hubble Diagrams

35 Two parenthetical remarks about Elias et al. (1985): This paper was the first to recognize SNe Ib as a separate class of Type I SNe The term SN Ia was first used to describe classical Type I SNe