Intermediate luminousity Red Transients

Nadia Blagorodnova

iPTF summer school, 20th July 2016

in collaboration with Mansi Kasliwal, Jacob Jenson (Caltech), Rubina Kotak, Joe Polshaw (QUB) Transients in the “gap”

PTF11agg 46 −26 10 iPTF13dsw

−24 Relativistic Explosions 45 Luminous Supernovae 10 SCP06F6

SN2005ap SN2008esPTF09cnd −22 SN2006gy PTF09atu 44 iPTF13bxl PTF10cwr PTF09cwl 10 SN2007bi −20 ] Thermonuclear V

43 ]

Supernovae 1

SN2002bj 10 − −18

PTF10bhp PTF12bho Core−Collapse .Ia Explosions SN2007ke Supernovae 42 −16 PTF11bij PTF09dav 10 PTF10xfh PTF11kmb SN2012hn PTF10iuv SN2005E Ca−rich Transients −14 SN2008ha 41 SN2008S Intermediate 10 PTF10acbp Luminosity NGC300OT Red Peak Luminosity [erg s

Peak Luminosity [M −12 Transients 40 PTF10fqs 10

−10 P60−M82OT−081119 Luminous M85 OT Red V838 Mon Novae 39 Classical Novae M31 RV 10 −8 P60−M81OT−071213

38 −6 V1309 Sco 10

−4 −1 0 1 2 10 10 10 10 Characteristic Timescale [day] Kasliwal et. al., 2011 Observational signature? Characteristics

6 8 • Peak absolute mags -10 > Mbol > -15 (10 - 10 L sun)

• Timescales similar to SNe (~months)

• Red continuum: 3000 - 4000 K

• Spectra shows narrow H emission lines in emission (FWHM ~ few 100-2000 km/s) and other low ionization lines (e.g., Ba I, Na I, Ca II, Fe II) Families of intermediate luminosity transients

• LBV (SN impostors) • faint SNe • Stellar mergers

• Massive star • Terminal • Remnant is a eruptions explosion rejuvenated star • Dust- • Multiple obscured SNe outbursts • Circumstellar • e- capture on disk • e.g. Eta CONe core Carinae, • e.g. V1309 P-Cygni, UGC • e.g. SN2008S, Sco, V838 Mon 2773-OT NGC300-OT Luminous Blue Variables Supermassive single stars

CCSNe

Parameters: Initial MASS + metallicity Classical examples

UGC2773-2009OT Humphreys et al. 2016

Smith et. al., 2016 faint SNe (with dusty progenitors?)

NASA/JPL-Caltech/R. Hurt (SSC/Caltech) Low mass single stars

CCSNe

ecSN?

Parameters: Initial MASS + metallicity NGC 300-OT

Prieto et. al., 2009

Optical IR MIR

T1~3890 K T2 ≈ 1500K T~485K PTF10fqs

M99

Progenitor limits: Kasliwal et. al., 2011 Mg ≈ −4 (<7 Msun) Luminous Red Novae LRN originate from binaries… which are common!

Observational Theoretical

49/71 systems

fbin = 0.69 ± 0.09 De Mink et al. (2013) Sana et al. (2012) Binary stars

Parameters: Initial MASSES M1+M2, period, metallicity

CASE 1 : not interacting

CASE 2 : interacting

(a) M1

(b) Roche Lobe

M2 M1 < M2 M1 CM

A Numerical approximation to the radius of Roche Lobe (RL):

Relative RL position Mass transfer to M1 Eggleton, 1984 • Case A: main sequence burning hydrogen

• Case B: finished hydrogen burning, but not helium burning in the core

• Case C: the star has completed core helium burning

Paczynski, 1971 Evolution channels

(a) M1

(b) CHANNEL 1: CHANNEL 2: Stable mass transfer CE + spiral in (c1) (c2)

(2) (1)

Close binary pair Merged star The smoking gun… V1309 Sco

Tylenda et. al., 2011 Exponential period decay

Tylenda et. al., 2011 V838 Mon

Galactic merger at 6.1 kpc

Bond et. al., 2003 M101-2015OT-1 iPTF13afz +400 days

-10 yr The 16 year light curve

Blagorodnova, et. al. submitted Radius-temperature evolution

-4000R during outburst - 3600K during outburst

7000K

220R Spectral evolution

Continuum = 3600K

H alpha at 300km/s

TiO molecular bands

Other red transients Recombination of the ejecta?

Ivanova et. al. 2013 Shocks in outflows from L2?

Pejcha et. al. 2016 Conclusions

• Intermediate luminosity red transients have a well defined observational locus

• Disentangling the true nature of the outburst is a complex scenario

• Long time multi-wavelength monitoring

• Need for models to constrain the parameters of the system given the observables

• PTF has detected a sample (~20) of red transients in nearby galaxies.

• Further reading:

• Humphreys & Davidson, 1994 (LBV)

• Ivanova, et. al. 2013 (Common Envelope)

• Tylenda et. al. 2011 (V1309 Sco LRN)