SN 2010kd - A Superluminous Pair-Instability Supernova?

SN 2010kd - A Superluminous Pair-Instability Supernova?

SN 2010kd - A Superluminous Pair-Instability Supernova?

J.Vinkó

J.Vinkó ^{1,2 1,2} , W.Zheng , W.Zheng ^{3 3} , S.B.Pandey , S.B.Pandey ^{3,5 3,5} , R.Quimby , R.Quimby ^{4 4} , A.Romadan , A.Romadan ^{3 3} , R.Roy , R.Roy ^{5 5} , K.Takáts , K.Takáts ^{2 2} , , E.Chatzopoulos

E.Chatzopoulos ^{1 1} , J.C.Wheeler , J.C.Wheeler ^{1 1} , F.Yuan , F.Yuan ^{6 6} , C.Akerlof , C.Akerlof ^{3 3} , D.Pooley , D.Pooley ^{7 7}

1 1 University of Texas at Austin, TX: University of Texas at Austin, TX: vinko@astro.as.utexas.edu vinko@astro.as.utexas.edu ; ; ^{2 2} University of Szeged, Hungary; University of Szeged, Hungary; ^{3 3} University of Michigan, MI; University of Michigan, MI;

4 4 IPMU University of Tokyo; IPMU University of Tokyo; ^{5 5} ARIES Nainital, India; ARIES Nainital, India;

6 6 RSAA Australian National University, Australia; RSAA Australian National University, Australia; ^{7 7} Sam Houson State University, TX Sam Houson State University, TX

Superluminous supernovae Superluminous supernovae

In the last decade a new class of stellar explosions was discovered:

In the last decade a new class of stellar explosions was discovered:

Superluminous Supernovae (SLSNe). While being spectroscopically diverse, their Superluminous Supernovae (SLSNe). While being spectroscopically diverse, their

common property is the very high peak brightness -- they are all brighter than -21 common property is the very high peak brightness -- they are all brighter than -21

magnitude in all optical bands (Quimby, 2011; Gal-Yam, 2012).

magnitude in all optical bands (Quimby, 2011; Gal-Yam, 2012).

SN 2010kd was discovered by the ROTSE Supernova Verification Project with SN 2010kd was discovered by the ROTSE Supernova Verification Project with

the ROTSE-IIIb telescope at McDonald Observatory on Nov.14, 2010 (Vinko et the ROTSE-IIIb telescope at McDonald Observatory on Nov.14, 2010 (Vinko et

al. 2010). Its redshift was estimated from the narrow H

al. 2010). Its redshift was estimated from the narrow H α α emission of the emission of the underlying host galaxy as z = 0.101, implying a distance of ~415 Mpc (adopting underlying host galaxy as z = 0.101, implying a distance of ~415 Mpc (adopting H H

₀₀

= 73 km/s/Mpc). The measured brightness of 17 mag corresponds to -21 = 73 km/s/Mpc). The measured brightness of 17 mag corresponds to -21

absolute magnitude, suggesting that SN 2010kd is a SLSN.

absolute magnitude, suggesting that SN 2010kd is a SLSN.

Spectroscopic evolution Spectroscopic evolution

References References

Chatzopoulos, E., Wheeler, J.C., Vinko, J. 2012, ApJ in press Chatzopoulos, E., Wheeler, J.C., Vinko, J. 2012, ApJ in press Chatzopoulos, E. & Wheeler, J.C. 2012, ApJ in press

Chatzopoulos, E. & Wheeler, J.C. 2012, ApJ in press Gal-Yam, A. et al. 2009, Nature 462, 624

Gal-Yam, A. et al. 2009, Nature 462, 624 Gal-Yam, A. 2012 Science, in press

Gal-Yam, A. 2012 Science, in press Quimby, R. et al. 2011, Nature 474, 487 Quimby, R. et al. 2011, Nature 474, 487 Young, D. R. et al. 2010, A&A 512, 70 Young, D. R. et al. 2010, A&A 512, 70 Vinko, J. et al. 2010,

Vinko, J. et al. 2010, CBETCBET 2556 2556

This work has been supported by the following grants: NSF AST-1109801; Hungarian This work has been supported by the following grants: NSF AST-1109801; Hungarian OTKA K76816. The presentation is supported by the European Union and co-funded by OTKA K76816. The presentation is supported by the European Union and co-funded by the European Social Fund. Project title: “Broadening the knowledge base and supporting the European Social Fund. Project title: “Broadening the knowledge base and supporting the long term professional sustainability of the Research University Centre of Excellence the long term professional sustainability of the Research University Centre of Excellence at the University of Szeged by ensuring the rising generation of excellent scientists.”

at the University of Szeged by ensuring the rising generation of excellent scientists.”

Project number: TÁMOP-4.2.2/B-10/1-2010-0012 Project number: TÁMOP-4.2.2/B-10/1-2010-0012

Photometry and light curve fitting Photometry and light curve fitting

Date of Date of

observation

observation Age in Age in rest-

rest- frame frame (days) (days)

RR_{B BB B} (10(10¹⁵¹⁵ cm)cm)

TT_{B BB B} (K)(K)

vv_{O IO I}

(km/s) (km/s)

Telescope Telescope

2010-11-22

2010-11-22 +36+36 2.162.16 1355413554 99609960 HETHET 2010-11-26

2010-11-26 +40+40 2.112.11 1399913999 1027610276 HETHET 2010-11-27

2010-11-27 +41+41 2.472.47 1226312263 1101211012 HETHET 2010-11-28

2010-11-28 +42+42 2.552.55 1212812128 97509750 HETHET 2011-01-04

2011-01-04 +75+75 2.992.99 1113011130 97859785 HETHET 2011-01-23

2011-01-23 +93+93 3.423.42 97349734 95049504 HETHET 2011-03-26

2011-03-26 +149+149 3.863.86 70137013 72977297 KeckKeck 2011-05-13

2011-05-13 +192+192 2.302.30 73767376 71567156 HETHET 2011-07-02

2011-07-02 +238+238 2.482.48 58185818 67716771 KeckKeck

The host galaxy The host galaxy

There are 3 objects on the SDSS frame within the error circle of ROTSE. The

brightest one is SDSS J120800.90+491333.1, a galaxy with a photo-z of 0.095.

Fig.1:

Fig.1:

Observed spectra Observed spectra

of SN 2010kd.

of SN 2010kd.

The lack of both The lack of both

H and He means a H and He means a

peculiar Type Ic, peculiar Type Ic, similar to 2007bi similar to 2007bi

(Gal-Yam et al., (Gal-Yam et al.,

2009; Young et al.

2009; Young et al.

2010).

2010).

Fig.2:

SYNOW model of the pre- maximum spectrum, dominated by CII, OII and OI. The drop of the UV- flux observed by Swift can be fitted with CoIII.

Fig.3:

Fig.3:

SYNOW models for post-SYNOW models for post- maximum spectra. Mg II, SiII and maximum spectra. Mg II, SiII and

FeII features have strengthened. HeI FeII features have strengthened. HeI

and CII are unlikely to be present.

and CII are unlikely to be present.

Table 1:

Table 1:

Physical Physical

parameters parameters

(age, blackbody radius, temperature, radial velocity) inferred (age, blackbody radius, temperature, radial velocity) inferred

from the spectra.

from the spectra.

Fig.7:

Fig.7:

the host galaxy on the SDSS DR8-frame. the host galaxy on the SDSS DR8-frame.

Absolute magnitude is M

Absolute magnitude is M_gg = -16.8 mag. = -16.8 mag.

Fig.8:

Fig.8:

the SED of the presumed host galaxy the SED of the presumed host galaxy (SDSS, red circles) is well fitted by an Sc-type (SDSS, red circles) is well fitted by an Sc-type

galaxy template. From the observed narrow galaxy template. From the observed narrow

emission features (blue curve) we derive emission features (blue curve) we derive

12+log(O/H) = 7.88

12+log(O/H) = 7.88 ±± 0.05. 0.05.

The host is a metal- poor dwarf galaxy, similar to The host is a metal- poor dwarf galaxy, similar to

other SLSNe hosts.

other SLSNe hosts.

Ground-based UBVRI-photometry was carried out at Aryabhatta Ground-based UBVRI-photometry was carried out at Aryabhatta

Research Institute, Nainital, India. In addition,

Research Institute, Nainital, India. In addition, Swift Swift UVOT and UVOT and XRT observations were obtained around maximum light. The SN XRT observations were obtained around maximum light. The SN

was detected as a strong source in UV, but not in X-rays.

was detected as a strong source in UV, but not in X-rays.

Swift UBV 2010-12-19

Swift UV 2010-12-19 SN 2010kd

Fig.4:

Fig.4:

Swift

Swift UVOT optical UVOT optical (left) and UV (right) (left) and UV (right) true-color image of true-color image of

SN 2010kd.

SN 2010kd.

Fig.5:

Fig.5:

Ground-based (filled Ground-based (filled circles) and Swift UVOT (open circles) and Swift UVOT (open

circles, filled squares and circles, filled squares and triangles) light curves of SN triangles) light curves of SN 2010kd. The SN reached maxi- 2010kd. The SN reached maxi- mum brightness on 2010-12-22, mum brightness on 2010-12-22, about 60 rest-frame days after about 60 rest-frame days after

explosion.

explosion.

Fig.6:

Fig.6:

Light curve models of Light curve models of

Ni-Co-Fe radioactive decay (red), Ni-Co-Fe radioactive decay (red),

magnetar spin-down (green) and magnetar spin-down (green) and

shock-heated CSM interaction shock-heated CSM interaction

(blue; see Chatzopoulos et al. 2012) (blue; see Chatzopoulos et al. 2012)

fitted to the ROTSE data.

fitted to the ROTSE data.

Conclusions Conclusions

The observed peak brightness needs 56-Nickel mass of

The observed peak brightness needs 56-Nickel mass of M M

_{N iN i}

~10 ~10 M M

_{S u nS u n}

, , which may suggest a Pair-Instability (PI) explosion. However, the

which may suggest a Pair-Instability (PI) explosion. However, the observed risetime is indicative of ejected mass between 20 - 30

observed risetime is indicative of ejected mass between 20 - 30 M M

_{S u nS u n}

, , a factor of 2 lower than the theoretical lower mass limit (~65 M

a factor of 2 lower than the theoretical lower mass limit (~65 M

_{S u nS u n}

) of ) of the PI mechanism (Chatzopoulos & Wheeler, 2012). Alternative

the PI mechanism (Chatzopoulos & Wheeler, 2012). Alternative

models for the power source of the light curve, such as magnetar or models for the power source of the light curve, such as magnetar or

CSM interaction, cannot be ruled out.

CSM interaction, cannot be ruled out.