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Type Ia supernovae: progenitors and the determina5on of dark energy
Pilar Ruiz-‐Lapuente Groningen, April 2014
● Introduc5on ● Type Ia supernovae at z close 2! ● Rising the standard for standard candles (GTC Project) ● Observing SNeIa in the infrared ● H0 from SNeIa
Supernova Comology in 2014
The Discovery of the Accelera5on of the Universe
Perlmu6er et al., incl. Ruiz-‐Lapuente (1999)
The Discovery of the Accelera5on of the Universe
Best-‐fit confidence regions in the ΩM – ΩΛ plane. The 68%, 90%, and 99% sta5s5cal confidence regions are shown (Perlmu6er et al., incl. Ruiz-‐Lapuente 1999)
The Discovery of the Accelera5on of the Universe Calibrated candles through the rela5on magnitude-‐ rate of decline
Pskvoskii-‐Branch effect (known in the 80’s)
Phillips (1993) Δm15
Riess, Press and Kirshner (1995)
MLCS
Perlmu6er et al. (1996): stretch s
σ≈0.15 mag
With color informa5on
σ≈0.11 mag
The Discovery of the Accelera5on of the Universe
There are three different possible distance measurements in Cosmology: from the brightness of objects of known luminosity, from the angular size of objects of known dimension, and from the proper (angular) mo5on of objects traveling with known velocity perpendicularly to the line of sight. Each of them is related to the redshid z via the cosmological parameters q, ΩM, ΩΛ, and Ωk The luminosity distance, dL, is simply defined as
where L is the luminosity and f the measured flux. As a func5on of z, H0, and q0
But more interes5ng is the full dependence on the three density parameters ΩM , ΩΛ , and Ωk :
where sinn(x) = sin(x), x, or sinh(x) for closed, flat, and open universes, respec5vely
Standardizable candles
The Discovery of the Accelera5on of the Universe
Riess et al. (2007)
The Discovery of the Accelera5on of the Universe
Combined SNIa, CMB and BAO constraints in the (ΩM , w) plane
(w ≡ p/ρ ; w = -‐1 for vacuum energy)
Amanullah et al., incl. Ruiz-‐Lapuente (2010)
The Discovery of the Accelera5on of the Universe
Confidence regions in the (w0 , wa) plane, combining SNeIa, CMB, and BAO
w(z) = w0 + wa z/(1+z)
Amanullah et al., incl. Ruiz-‐Lapuente (2010)
The Discovery of the Accelera5on of the Universe
Union2
w = -‐0.997 ± 0.08 (flat) w = -‐1.038 ± 0.09 (allowing curvature) At z ≥ 1 the existence and nature of dark energy are only weakly constrained by the data
Amanullah et al., incl. Ruiz-‐Lapuente (2010)
The Discovery of the Accelera5on of the Universe
The cosmological constant case (bold line) is compared with evolving models close to w = -‐1, i.e., a model with w0 = -‐1.0 and wa = -‐1.5 (short dashed line) and a model with w0 = -‐1.0 and wa +1.5 (dash-‐doled line). Only very accurate measurements will enable to discriminate among different equa5ons of state
The Discovery of the Accelera5on of the Universe
ACS image of the SN loca5on. Lower right panel shows a composite image from the three colors. Lines indicate the dispersion direc5on in ACS (dashed) and WFC3 (doled) spectroscopy (Rubin et al. 2013)
Redshid 1.71 supernova
Each panel shows a comparison between SN SCP-‐0401 and another SN. Best-‐matching comparison SN Ia in the led panels, best-‐matching CC SN in the right panels. Best match is for SN1992A. Out of 17 CC SN, only SN1983N is a possible match, but it was 2 mag fainter than any typical SN Ia (Rubin et al. 2013)
Redshid 1.71 supernova
Redshid 1.71 supernova
Most recent SCP Hubble diagram, with Primo (Rodney et a. 2012) and SCP-‐0401 SNe added (Rubin et al. 2013)
The Cosmic Assembly Near-‐IR Deep Extragalac5c Legacy Survey, CANDELS (Grogin et al. 2011; Koekemoer et al. 2011), PI: S. Faber, Co-‐PI, H. Ferguson, is designed to document the first third of galac5c evolu5on from z = 8 to 1.5 via deep imaging of more than 250,000 galaxies with WFC3/IR and ACS. It will also discover and characterize Type Ia SNe beyond z > 1.5 and establish their accuracy as standard candles for cosmology
CANDELS
Rodney et al. (2012)
CANDELS
z = 1.55
Most distant SN Ia to date
z = 1.914
Jones et al. (2013)
Most distant SN Ia to date
Jones et al. (2013)
Systema5c uncertain5es: ● Dust ex5nc5on ● Possible evolu5on of the intrinsic proper5es of SNeIa Evidence of two dis5nct popula5ons of SNeIa hosts: SNeIa in early-‐type galaxies can be dis5nguished from those that occur in late-‐type galaxies
Precision cosmology with SNeIa
SNeIa in progenitor popula5ons ● Currently , using SALT2.2 to correct for light curve shape (x1 parameter) and
color excess (c), from the apparent peak blue magnitude mB, the distance modulus is given by:
μSN = mB – MB – αx1 + βc where α, β, and MB are nuisance parameters determined simultaneously with
cosmological parameters. That reduces the scaler of μSN about the best-‐fit model to ≈15%, down from the ≈50% scaler for uncorrected absolute peak magnitudes
● Ader those correc5ons, however, it was said that SNeIa in passively evolving
or massive galaxies are slightly brighter than those in star-‐forming or less massive galaxies (the bigger-‐brighter correla5on)
● Need to understand the physics of SN Ia brightness varia5ons and of empirical
brightness calibra5ons and the possible evolu5on of those calibra5ons and of SN Ia demographics
SNeIa in passive progenitor popula5ons
Meyers et al., incl. Ruiz-‐Lapuente (2012)
SNeIa in passive progenitor popula5ons
Possible theore5cal interpreta5on: ● C mass frac5on in C+O white dwarfs is smaller if the stars formed in lower metallicity or older environments. They produce fainter SN Ia (Umeda et al. 1999)
Meyers et al., incl. Ruiz-‐Lapuente (2012)
Current and Near Future Projects
Kim et al. (2013)
The Hubble constant
The Hubble constant
PRL (1996)
H-‐band SN Ia Hubble diagram. It includes 23 SN Ia observed with PAIRITEL (Wood-‐Vasey et al. (2008)
A new proposal
SNeIa for Cosmology at high redshid
● We have observed, for the first 5me, SNeIa at z > 1.5 ● The most distant SNeIa fit the ΛCDM model ● Stretch mainly depends on the ages of the SNeIa progenitor ● It appears that SNeIa are beler standard candles in the infrared, no stretch correc5on being needed there. That will be exploited by the upcoming NASA observatory JWST
Search for SNeIa companions
Search for SNeIa companions
Possible companions of the exploding white dwarf in a SN Ia
● Main-‐sequence stars
● Subgiants
● Red giants
● AGB stars
● Helium stars
Search for SNeIa companions
Search for SNeIa companions
The problem of the nature of the binary systems giving rise to Type Ia (thermonuclear) supernovae: single-‐degenerate channel (with several possibili5es) or double-‐degenerate channel? • From recent Type Ia supernovae in nearby galaxies (SN 2011fe in M101, at 6.4 Mpc,
and SN 2014J in M82, at 3.5 Mpc only), it has been possible to rule out , from pre-‐explosion images, red-‐ giant companions in the second case and just very luminous companion stars in the first one
New method • A method based consis5ng of the direct search for companion stars in the central
regions of recent, close-‐by SNeIa (in our Galaxy and in the Magellanic Clouds) has been proposed (RL 1997) and
it has proved to be very fruiyul • Based on the expected characteris5cs of any kind of SN companion
• Type Ia SNe impact the companion star → strip part of the envelope → heat up the envelope → enrichment in metals • Calcula5ons of this process • Wheeler, Lecar & McKee (1975); Marie6a, Burrows & Fryxell (2000); Pakmor et
al. (2008); Pan, Rickert & Taam (2012); Liu et al. (2012)
• We simulated, for typical distances, which would be the likelyhood of finding a perturbed star
RL 1997; Canal, Méndez & RL 2001; RL et al. 2002 → kick + orbital velocity → high radial velocities + proper motions • The region to be searched depends on the distance to the SNIa and the age
SN 1572 and SN 1006 very good candidates
Search for SNeIa companions
• Survey of the central regions of historical Galacdc SNeIa remnants (RL 1997; RL et al. 2004; Gonzalez-‐Hernandez, RL et al. 2009
Kerzendorf et al. 2009, 2012; GH, RL et al. 2012)
● SN (Tycho) 1572 • SN 1006 • Recently extended to the LMC (Schaefer & Pagnola 2012; Edwards et al. 2012)
Search for SNeIa companions
Direct searches
SN 1572
Ground-‐based op5cal image of the region surveyed to search for the binary companion of SN 1572
(from Ruiz-‐Lapuente, et al. 2004)
SN 1572
Sec5on of the Galac5c plane, in the direc5on of Tycho’s SNR. The average radial velocity (referred to the LSR) is shown. At the distance of the SNR, it is in the range -‐20 to -‐40 km/s
SN 1572
SN 1572
SN 1572
SN 1572 A normal SNeIa (RL 2004; Krause et al. 2008) Nonthermal X-‐ray arc inside the SNR possibly indica5ng interac5on of the ejecta with the envelope of the companion (Liu et al. 2011) • RA: 00 25 19.9 DEC: +64 08 18.9 (J2000.0) • D = 2.83 ± 0.79 kpc • Located 59-‐78 pc above the Galac5c plane • SNR radius ≈ 4 arcmin Highly reddened field : E(B-‐V) ≈ 0.6 Surveyed 15% of the innermost radius (0.65 arcmin) of the SNR, down to mV = 22 (the Sun would have mV = 18.9 at that D) both photometrically and spectroscopically • Modeled the spectra to obtain Teff, log g, [Fe/H] and derived distances using the
photometry (RL et al. 2004; GH, RL et al. 2009)
• Measured radial veloci5es from the spectra and proper mo5ons from HST astrometry
• Found a subgiant star (G0-‐1 IV) with peculiar radial velocity for its distance and also very high proper mo5on (star G)
SN 1572
HST (ACS) image of the central region of the SNR of SN 1572
SN 1572 0.5 arcmin circles around three different proposed centers of the remnant of SN 1572, plus the 0.65 arcmin circle around the adopted center of the survey (the Chandra X-‐ray center). The current posi5ons of the stars are compared with those in 1572, based on the proper mo5ons measured
(from Ruiz-‐Lapuente, et al. 2004)
SN 1572
(from Ruiz-‐Lapuente, et al. 2004)
SN 1572
Two different regions of the Keck HIRES spectrum of the star Tycho G, showing several Ni lines
SN 1572
Abundance ra5os of Tycho G, compared to those of G and K metal-‐rich dwarf stars (the dispersion is of 0.04 dex only, for the Ni abundances)
(from González Hernández, Ruiz-‐Lapuente, et al. 2009)
SN 1572
(from Bedin, Ruiz-‐Lapuente, et al. 2014)
SN 1572
(from Bedin, Ruiz-‐Lapuente, et al. 2014)
SN 1572
• At D ≈ 3 kpc, stars close to the Galac5c plane move at vr ≈ -‐20/-‐40 km/s (LSR), while star G is moving at vr ≈ -‐80 km/s • For D ≈ 3 kpc, a proper mo5on µb ≈ -‐4 mas/yr means a velocity, perpendicular to the Galac5c plane, vz ≈ -‐60 km/s, while the disk’s velocity dispersion is σz ≈ 17 km/s only. The total vt ≈ 85 km/s at that distance • [Ni/Fe] = 0.16 ± 0.04 in star G, which is of about solar metallicity ([Fe/H] = -‐0.05 ± 0.04) Very low probability of finding a star unrelated to the SN within such a small area of the
sky and limited distance range ,
SN 1572
● Confirmed high velocity perpendicular to the Galac5c plane ● Shows Ni pollu5on ● Low rota5on velocity not par5cularly significant, from current hydrodynamic simula5ons ● Angular distance to centroid of X-‐ray emission well within uncertain5es
SN 1006
SN 1006
• RA = 15 02 55 DEC = -‐41 55 12 (J2000.0) (Allen et al. 2001, but see Winkler et al.
2003, 2005) • D = 2.18 ± 0.08 kpc • Located ≈ 0.5 kpc above the Galac5c plane • SNR radius ≈ 15 arcmin Low reddening: E(B-‐V) ≈ 0.1, as compared with the SN 1572 field Surveyed the region within 4 arcmin from the adopted center (≈ 27% of the SNR radius),
down to the luminosi5es of main-‐sequnce stars dimmer than the Sun Photometry from the USNO-‐A2.0 catalog: 26 stars selected Spectroscopy with VLT/UVES of the selected stars, with resolu5on R = 43,000
● R ≈ 43,000 in UVES → ∆vrot ≈ 7 km/s ● R ≈ 25,000 in FLAMES + GIRAFFE → ∆vrot ≈ 12 km/s
SN 1006
5-‐arcmin circle around the adopted center of the survey, with the posi5ons of the 26 stars, numbered according to their increasing distances from the center (see Tables)
S designates the adopted center of the survey, G is the geometrical center of the Hα emission determined by Winkler et al. (2003), and S-‐M is the posi5on of the Schweitzer-‐Middleditch star (a background star)
(from González Hernández, Ruiz-‐Lapuente, et al. 2012)
SN 1006
SN 1006
SN 1006
• Surveyed a large area around the center of the SNR. From the stellar parameters and the photometry, we see that only a small number of stars are at distances compa5ble with that of the SNR. ● No star , within the magnitude limit of our survey, has any peculiarity that could point to it as the companion of the SN. ● No evolved star can thus be the companion and any possible MS companion should be less luminous than the Sun.
SN 1006
Spectra of the 4 giant stars at distances marginally compa5ble with that of the SN 1006 SNR
(from González Hernández, Ruiz-‐Lapuente, et al. 2012)
SN 1006
SN 1006
Abundance ra5os of the surveyed stars (blue and red dots), compared to those of a sample of field stars (black dots) covering the same metallicity range. Red dots correspond to stars with distances compa5ble with that of the SNR
(from González Hernández, Ruiz-‐Lapuente, et al. 2012)
Kepler SNIa
SN 1604 SNR : spectroscopy of stars with mR ≤ 18, within a 3 arcmin radius around the X-‐ray center of the remnant, using FLAMES with UVES and GIRAFFE on the VLT (work in progress). Interes5ng case, since there are have been sugges5ons that the SN companion was a RG star
Search for SNeIa companions
Targeted stars for VLT spectroscopy and for PM measurements with the HST. Blue circle: 20% radius of the SNR. Green circle: 33% of the radius
Search for SNeIa companions
SNR 0509-‐67.5 in the LMC (from Schaefer & Pagno6a 2012)
Search for SNeIa companions
Search for SNeIa companions
SN took place 400 ± 50 years ago (from light echo) No star in the central region, down to MV = +8.4 (the Sun has MV = +4.5)
Search for SNeIa companions
SNR 0519-‐69.0 in the LMC (from Edwards, Schaefer & Pagno6a 2012)
Search for SNeIa companions
No stars down to V = 26.05 That eliminates red giant stars recurrent novae, and helium donors
Search for SNeIa companions
SNR G272.2-‐3.2
(from Harrus et al. 2001)
Search for SNeIa companions
● Five direct searches for companions (3 in the Galaxy, 2 in the LMC) have just produced 1 possible object (a SG star) up to now ● SN 2011fe and SN 2014J (a very nearby one) have not shown any evidence of a companion star. Red giants and other luminous companions are ruled out ● From X-‐ray and radio surveys, the same conclusions are reached (see review by Ruiz-‐Lapuente 2014)
EXCLUDED!
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