Lessons learned from the type Ia SN 2014J“Transients for all meeting” in Lund 2015

Rahman Amanullah

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• Discovered on January 21, 2014 (Fossey et al., 2014, 35 cm telescope)

• Spectroscopic confirmation by iPTF

• Explosion took place on January 15, 2014

• About 30 papers have been published so far

SN2014J d = 3.5(0.3) Mpc (Delcanton et al., 2009) !SN1972E d = 2.5 — 8.0 Mpc

SN1986G d = 3.8(0.1) Mpc

SN2011fe d = 6.4(0.7) Mpc

1 kpc

A unique opportunity to learn more about SNe Ia, their environment, extinction along the line of sight

Detection in ɣ-rays3

A SN Ia is thermonuclear explosions of a C/O WD where the lightcurve is powered by the decay chain Maximum ɣ-ray

emission expected 70-100 days past explosion

Diehl et al. (2014) using INTEGRAL data starting at 16.6 days past explosion find early ɣ-ray detection. Surface radioactivity?

SN Ia model:

From ɣ-lines:

Churazov et al. (2014)

Host

Model at 75 days

50 - 100 days past explosion

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From Or Graur’s 2 min video presentation of his thesis (PhD comics)

Predictions for the single degenerate scenario, for example: Pre-explosion images? Circumstellar material? Left-over material of the SN companion? SN-ejecta interaction with companion in the early lightcurve?

Early rise-time of SN 2011fe5

Arnett (1982), Riess et al. (1999): a simple model where the SN luminosity that is powered by radioactive heating. At very early times the luminosity should be roughly proportional to the square of the time since explosion. Expanding “fire ball”

Bloom et al. (2011)

Progenitor:

Companion:

Nugent et al. (2011), Bloom et al. (2011):

Early detection was possible6

Zheng et al. (2014) Goobar et al. (2014)

Residuals for method 1

What can we learn from studying the early rise?

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Shock heated ejecta

Progenitor

Companion

Kasen (2010)t1 4 x t1

a = separation distance

Shock heated companion

Goobar et al. (2015)

Goobar et al. (2015)

Kilodegree Extremely Little Telescope (4.2cm, 26 x 26 degree)

iPTF H-alpha

Non-detection in pre-explosion HST images (Goobar+ 2014, Kelly+ 2014) !Non-detection in X-ray (Margutti+ 2014) and radio (Pérez-Torres+ 2014)

R larger than expected for a compact object but could be consistent with some WD-merger models

Rabinak & Waxman, 2011

Compared to SN 2011fe8

Lightcurve resembles that of SN2011fe when reddening is taken into account

Spectroscopic normal SN Ia with high expansion velocities (e.g., Goobar+ 2014, Marion+ 2014)

HST

The origin of SN color?9

Extinction

Host galaxy

SN environment

SN

Milky Way

Observer

−0.2 −0.1 0.0 0.1 0.2Color

−1.0

−0.5

0.0

0.5

1.0

Betoule et al. (2014)

Intrinsic variability

Blue Red

Faint

Bright

The reddening of SN 2014J10

uvm2

F275WF225W F218WF336WU

B

Ri

Brown et al. (2014)

Low RV, (Galactic RV=2-6) extinction law is not varying with time, but Foley+ (2014), using HST spectra between -6 and +24 does find the extinction law to vary.

See also Goobar+. Brown+, Marion+ and Ashall+ (2014)

Absorption in the CSM/ISM11

Also, see poster by Raphael Ferretti!

See also: Goobar+, Fooley+, Welty+ (2014), Ritchey+, Graham+ (2015)

Support for “circumstellar” dust

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Graham et al. (2015)

Time-variation in six epochs (-11 — +22) of K I (but not in the corresponding Na I D lines). This is consistent with CS material at r = 1019cm

Crotts (2015) claims at least one light echo at 80 pc.

Re-emission from circumstellar dust in mid-IR

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Constraints for a simple model of a heated dust cloud (red lines/contours)

Thin shell with τ(V)~1

14J at +29d

14J at +157d

Excluded fromSpitzer limits

Thin shell approximation (blue lines/contours) allows to constrain the shell radii at two epochs (black lines) rd>1017cm

Six epochs of Spitzer observations at 3.6 and 4.5 µm.

Johansson et al. (2015)

Summary

■ Progenitor: First detection of ɣ-ray consistent with WD exploding. Surface material? Early rise-time consistent with this, early ɣ-ray detection.

■ Environment: no CSM interaction detected in radio or x-ray and no excess in MIR constraining, rd > 1019 cm. No variability in Na I D but has been seen in K I. Consistent with CS dust at r=1019 cm. Light echo has been observed at high radii!

■ Extinction: Another highly reddened SN Ia with low, RV=1.4. (Galactic: RV=2-6), based on data with λ=0.2—2.2 μm. CS dust seems to be disfavoured for explaining this. Small grain sizes?

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