A Blunder Undone. Robert P. Kirshner Harvard-Smithsonian Center for Astrophysics. Robert P. Kirshner Harvard University

Transcription

1 A Blunder Undone Robert P. Kirshner Harvard-Smithsonian Center for Astrophysics Robert P. Kirshner Harvard University

2 I think it must be static!

3 Hubble s 1929 Diagram Redshift proportional to distance: distances from Cepheid variables and from galaxy properties

4 L! Hau ab!

5 Georges Lemaître S.J. + MIT Ph.D. Everything happens as though the energy in vacuo would be different from zero we associate a pressure p= -rc 2 to the density of energy rc 2 of vacuum. This is essentially the meaning of the cosmical constant l. PNAS 20, 12 (1934)

6 Hubble in The Realm of the Nebulae Supernovae can be detected at immense distances and, in principle, they are a criterion of distance about as reliable as that of total luminosities of the nebulae. Actually, however, the maxima are so seldom observed and the [super]novae themselves are so rare that they contribute very little to the present problem.

7 Thermonuclear exploding stars ~ 4 x 10 9 Suns 10 6 brighter than the stars Hubble used ~1 SNIa /century in a galaxy

8 1/100 years ~ 1/5000 weeks => 5000 galaxies

9 Fritz Palomar The 18 Schmidt

10 The Beginning of Supernova Cosmology Charlie Kowal ( ) Note the imaging technology of 1968! Monthly searches in the dark of the moon at Palomar with 48 and 18

11 Kowal (1968) Had distances good to ~30% from SN I Speculated that individual measurements might be good to 5-10% It may even be possible to measure the second-order term in the redshiftmagnitude relation when light curves become available for very distant supernovae.

12 Technology of the 1990s: CCD: 0.24 Megapixels

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14 Light Curves: Clues to Luminosity Related to 56 Ni produced in the explosion Pskovskii (1977,1984) Mark Phillips (1992) Riess, Press & Kirshner (1995, 1996) Goal: better distances, determination of extinction by dust

15 Supernovae are imperfect standard candles they vary by a factor of 2! But we can tell which are bright and which are dim from the light curve shape and which are dimmed by dust from the color. Mandel, Narayan, Kirshner ApJ 731, 120 (2011) B r i g h t D i m SLOW FAST

16 Today s nearby Hubble diagram for Supernovae CfA1,2,3

17 Today s nearby Hubble diagram for Supernovae

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19 a H o = a /a a /a the acceleration

20 We expected Deceleration! Searching for a /a ~ - (r + 3p) = - (1 + 3w)r cosmic w gives the equation of state: p/r deceleration w = -1 for the cosmological constant- - negative pressure, positive acceleration! a ~ q o ~ -(W m /2 + W L ) So, for W L = 0, expect to see deceleration

21 1998 Data: HZT: Riess et al. Astronomical Journal September SN Ia Low z from Calan/Tololo & CfA SCP: Perlmutter et al. Astrophysical Journal June SN Ia Low z from Calan/Tololo

22 1990:Theoretical Consensus W total = W m = (but observers knew W m was 0.3) 1995: some discussion of W L =W total W m Ostriker & Steinhardt Turner & Krauss Chief objection was SCP supernova result widely reported (Critical Dialogs June 1996) and published in 1997

23 All truths are easy to understand once they are discovered; the point is to discover them.

24 Today s Sample~500 SN Ia

25 DARK MATTER D A R K E N E R G Y

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27 Looks easy now! Figure from Ariel Goobar

28 The diagram is full!

29 What do the supernovae measure? Cosmic Age! (H o t o ) W L - W m : the difference between the acceleration due to the dark energy and the braking due to gravitation Perpendicular to CMB which measures W L + W m

30 Cannot tell from expansion history alone- growth of structure Is the Dark Energy the Cosmological Constant? Not good quantitative agreement! Anthropic selection from a landscape? Ugh! Other possibilities: Something that is not constant Quintessence or other scalar Modifications to gravity? f(r)

31 From Sullivan et al (SNLS results) 1 + w = / (statistical + systematic) + Low-z Importance of photometric calibration Betoule et al A & A 552,124 (2013)

32 Allen et al. (2013) arxiv: v1

33 w is More difficult! w = p/r w =-1 for Cosmo constant (1 + w = 0) Thanks again to Ariel Goobar

34 The Future

35 Finding SN with Pan-STARRS Medium-Deep Fields Good light curves at z~0.4 Every 4 days griz 7 square degrees 0.26 /pixel Dozens of supernova candidates every month!

36 PanSTARRS SN Ia Sample Rest, A. et al. ArXiV: Spectroscopically Confirmed SN Ia with griz light curves from PanSTARRS (MMT, Gemini, Magellan)

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39 PanSTARRS measures both low-z and high Scatter at low-z same as high not just measurement error-- more to be learned about SN Ia!

40 First Cosmology Results Systematic Errors discussed at length by Dan Scolnic et al. ArXiv:

41 Dust both dims and reddens -- but less so in the infrared Krisciunas, Phillips, & Suntzeff ApJ Letters 602, 81 (2004) Wood-Vasey et al. ApJ 689, 377 (2008) Folatelli et al. AJ 139,120 (2010)

42 Make the measurements in the infrared! J, H, K s image from PAIRITEL A first attempt: Freedman et al. ApJ 704, 1036 (2009)

43 Seeing through the dirt B

44 Seeing through the dirt V

45 Seeing through the dirt Z

46 Seeing through the dirt J

47 Seeing through the dirt H

48 Seeing through the dirt K

49 Mandel et al. ApJ 731, 120 (2011) Kattner et al.pasp 124, 114 (2012)

50 Kaisey Mandel Won Savage Award from ISBA!

51 Most important slide of this talk! At H-band (1.6m) SN Ia really are standard candles (and there s much less trouble with dust!)

52 The payoff for nearby supernovae

53 Could we get this advantage for the high-z supernovae? RAISIN

54 Use the infrared camera on HST to get rest frame IR of cosmological SN Ia! SN IA in the IR = RAISIN 100 orbits in Cycle 20

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57 Find SN with Pan-STARRS

58 Get spectrum with MMT

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62 One or more observations from the following HST proposal have been scheduled for execution on SMS A5. The SMS begins 25-NOV :00:00(UT) and ends 02-DEC :00:00(UT). No action is required on your part unless you have a Real Time Contact. Please contact your Program Coordinator (PC) if you have any questions. Proposal Id: Program Id: C1X Title: RAISIN: Tracers of cosmic expansion with SN IA in the IR <<< PLEASE DO NOT RESPOND TO THIS MESSAGE >>>> Start time: 29 Nov :37:53 End time: 29 Nov :29:44 SCIENCE SPECTRAL PROP VISIT EXP NUM TARGET INSTRUM MODE APERTURES ELEMENTS N4 001 PS1-E WFC3/IR MULTIA IR F160W N4 001 PS1-E WFC3/IR MULTIA IR F160W N4 001 PS1-E WFC3/IR MULTIA IR F160W N4 001 PS1-E WFC3/IR MULTIA IR F160W ==============================================================================

63 RAISIN Scorecard 23 PanSTARRS targets 3 epochs of IR with HST in two near-ir bands Images without the supernovae will be complete by mid-2014

64 IR with WFC3 (a good test case for AFTA/WFIRST)

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67 Extinction A V (mag) Marginal Probability Density 0.6 PS1 Optical (68%, 95%) PS1 Optical + HST NIR m(z=0.43, LCDM, h=0.72) s m = s m = Predicted Distance Modulus m (mag) Predicted Distance Modulus m (mag)

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69 Dark Energy Survey Have found a few SN Ia: many more to come: Vineyard for future RAISINS!

70 BIG RAISIN? (5 year DES 2/month) s = +/- 0.02

71 Large Synoptic Survey Telescope

72 JWST the infrared Space Telescope 2018

73 Giant Magellan Telescope includes Texas & Texas A&M

74 SN Ia & Cosmic Expansion History Better resolution helps distinguish a supernova from its host galaxy 0.5 seeing HST 1.5 m GMT AO

75 Site in Chile

76 1 st Mirror Polished to Perfection

77 2 nd & 3 rd Mirrors Cast

78 The Ice Mirror!

79 D ou venons nous Ou sommes nous Ou allons nous Paul Gauguin 1897

80 High-Z Team at Nobel Prize Ceremony

81 END

82 Single degenerate

83 Double degenerate Moaz et al. ARAA 2014

84 It is a good rule not to put overmuch confidence in a theory until it has been confirmed by observation. I hope I shall not shock the experimental physicists too much if I add that it is also a good rule not to put overmuch confidence in the observational results that are put forward until they have been confirmed by theory. Sir Arthur Stanley Eddington ( )

85 K-corrections needed! Carnegie (Eric Hsiao) & CfA (Howie Marion) have a vigorous program to get the needed spectra Magellan & Gemini

86 Giant Magellan Telescope GMT Compared to HST-- Area: 10 2 Resolution: 10

87 Putting L on the Right Hand Side Harvard Club of Boston

88 An accelerating universe! Q cufflinks

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90 Hubble s firsthand account of these discoveries: The Realm of the Nebulae 1936 Silliman Lectures at Yale new edition from Yale Press

91 Hubble in The Realm of the Nebulae Why did it take from 1925 until 1929 for Hubble to get around to connecting Slipher s redshifts with his own distances? a natural inertia in the face of revolutionary ideas couched in the unfamiliar language of general relativity, discouraged immediate investigation.

92 Modeling SN Ia Light Curves: Using the Optical + IR to learn about dust and distance Kaisey Mandel, Gautham Narayan & RPK ApJ 731, 120 (2011)

93 The IR is not strongly correlated with the Optical

94 Log Number of SNe per year 1000 RPK 1987A Year Chart compiled by Mark Sullivan

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96 Today s Hubble diagram for SN Ia Intercept adds only ½% to uncertainty in H o => don t need to use any ancient supernovae! Use only calibrators that are observed in the same way as the modern Hubble flow sample: CCD. Improvement not likely from N 1/2 must improve the systematic effects

97 Cosmic Flows from SN Ia Turnbull et al. MNRAS 420,447 (2012)

98 Inference from flows Consistent with LCDM W m 0.55 s 8 = / This subject will benefit from larger, and more isotropic samples of SN Ia See also Weyant, Wood-Vasey, Wasserman, Freeman ApJ 732,65 (2011)

99 X-ray cluster data agree

100 Uncertainty in dust properties leads to uncertainty in dark energy!

101 Only in space! Rest frame IR measurements of z~1 supernovae are not possible from the ground Go as far into the IR as technically feasible! Sky is very bright in NIR: >100x brighter than in space Sky is not transparent in NIR: absorption due to water is very strong and extremely variable