The dynamical sky Two frontiers Joel Johansson, Uppsala university - - PowerPoint PPT Presentation

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The dynamical sky Two frontiers Joel Johansson, Uppsala university - - PowerPoint PPT Presentation

Mar 15, 2023 490 likes •675 views

The dynamical sky Two frontiers Joel Johansson, Uppsala university Time Wavelength Optical surveys faster! HSC, 1.7 deg 2 PS1, 7 deg 2 DES, 2.5 deg 2 PTF/iPTF, 7.3 deg 2 ZTF, 47 deg 2 LSST, 9.6 deg 2 1 deg Optical phase-space

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The dynamical sky – Two frontiers

Wavelength Time

Joel Johansson, Uppsala university

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Optical surveys – faster!

PTF/iPTF, 7.3 deg2 HSC, 1.7 deg2 ZTF, 47 deg2 1 deg LSST, 9.6 deg2 PS1, 7 deg2 DES, 2.5 deg2

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Optical “phase-space” of Transients

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Days from explosion (MJD - 56571.12)

5 10 15 20 25 30 35

Apparent AB Magnitude

15 16 17 18 19 20 21 22 23 PTF R-band 3σ limits Polynomial Fit Hours from explosion

10 20 30 40 50 16 17 18 19 20 21 22

P200 DBSP NOT ALFOSC FTS FLOYDS NOT ALFOSC Keck1 LRIS

Absolute Magnitude

  • 18
  • 17
  • 16
  • 15
  • 14
  • 13
  • 12
  • 11

The dynamical sky – GO FASTER!

  • Fast transients (e.g. orphan GRBs, Cenko+15)
  • Probe very final stages of stars lives!

– Companion star in Type Ia supernovae? (e.g. Kasen 2010) – Shock break-out in core-collapse SNe (e.g. Rubin+2015) – “Flash”-ionization of circumstellar material (e.g. Gal-Yam+2014)

iPTF13dqy (Yaron+17) First detection ~3 hours after explosion! First spectrum 3 hours after detection…

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Rapid (“Flash”) spectroscopy

Rest Wavelength (Angstrom)

3500 4000 4500 5000 5500 6000 6500 7000 7500 8000 8500

Scaled Fλ + shift (erg cm-2 s-1 Ang-1)

10-19 10-18 10-17 10-16 10-15 +21.1 hr +10.1 hr +8.9 hr +7.2 hr +6.2 hr +5.1 d +5.3 d +2.1 d +2.0 d +1.9 d +1.4 d KeckII KeckII KeckI P200 NOT NOT FTS FTS O V H He II N V O VI O IV

(iPTF13dqy, Yaron+17) Dense CSM within ~1015 cm Ejected during the final year at high rate (~10-3 M¤/yr)

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Rapid (“Flash”) spectroscopy

(Johansson in prep.) Sample of ~20 PTF SNe (+ few objects from literature) with flash- spectroscopy PTF has total of ~700 Type II supernovae. Still, not rare! ~14% of SNe II should show flash-features (Khazov+15)

C III? N IV ?

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The dynamical sky – Two frontiers

Wavelength Time

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The Spitzer InfraRed Intensive Transients Survey (SPIRITS)

  • 0.85 metre mirror
  • 5.2´ × 5.2´ FOV
  • IRAC, post-cryo: 3.6 and 4.5 µm
  • 190 nearby galaxies (< 20 Mpc )

The dynamical sky – GO REDDER!

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NGC 2403 (Credit: Howard Bond)

The dynamical sky – GO REDDER!

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10 100 1000 Time (Days)

  • 5
  • 10
  • 15
  • 20

3.6um Mid-IR Luminosity (Abs Mag)

Novae

metal-dominated (QU Vul) dust-dominated (V1668 Cyg)

Supernovae

Type Ia (SN2014J) Type IIb (SN2011dh)

Intermediate Luminosity Red Transients

Mid-IR ”Phase-space” of Transients

~150 transients: 40 supernovae 20 novae 60 “mysteries”

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100 200 300 400 500 600 Days

  • 8.0
  • 8.5
  • 9.0
  • 9.5
  • 10.0

Absolute Magnitude (3.6um)

C-AGB O-AGB RSG Extreme?

>1200 variables ~150 transients: 40 supernovae 20 novae 60 “mysteries”

Mid-IR ”Phase-space” of Transients

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Kasliwal et al. (in prep.)

10 100 1000 Time (Days)

  • 5
  • 10
  • 15
  • 20

3.6um Mid-IR Luminosity (Abs Mag)

Novae

metal-dominated (QU Vul) dust-dominated (V1668 Cyg)

Supernovae

Type Ia (SN2014J) Type IIb (SN2011dh)

Intermediate Luminosity Red Transients

14aje 14aei 14ajc 14axa

Mysteries = “SPRITES” No optical/NIR counterparts! (Kasliwal+2017)

Massive binaries driving shocks in molecular clous? Stellar mergers with dusty winds? Enshrouded SNe?

~150 transients: 40 supernovae 20 novae 60 “mysteries”

Mid-IR ”Phase-space” of Transients

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Type IIn/Ia-CSM Core-collapse SNe Type Ia SNe ”Impostors” Type IIn/Ia-CSM SNe e.g. Fox&Filippenko (2013) Core-collapse SNe Sample in Tinyanont+16 SN 2011dh (Helou+13) SN 2013ej (Mauerhan+17) SN 2014C (Tinyanont et al.) SN 2014bi (Johansson et al.) Type Ia SNe Sample in Johansson+17 SN 2014J ”SN Impostors” SNHunt248 (Mauerhan+17)

Mid-IR ”Phase-space” of SUPERNOVAE

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Type IIn/Ia-CSM Core-collapse SNe Type Ia SNe ”Impostors” SN 2014dt

  • Peculiar, subluminous ”SN Iax”
  • Nearby (M61 @ 12 Mpc)
  • Bright in the mid-IR!
  • Late time IR-rise

(>2 mags @ 4.5 μm)!

The IR surprise from SN 2014dt

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;c9bf5d Mid-IR excess from warm dust?

  • Mdust ≈ 10-5 M¤ at Tdust ≈ 700 K
  • Pre-existing or newly formed?

(Fox, Johansson et al., 2016)

  • No progenitor in archival HST-images
  • No signs of reddening/Na ID absorption…

(Foley et al. 2014, 2016)

20” 20”

Keck/LRIS, I-band, 5x240 sec. (2017-01-02)

The IR surprise from SN 2014dt

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Progenitor system in HST images. Luminous/blue Helium star, donor to accreting White Dwarf (McCully+14) Thermonuclear ”deflagration”

  • f a WD that doesn’t completely

unbind the star. (Kromer+13,15)

The IR surprise from SN 2014dt

SN 2014dt SN 2012Z

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  • 1. Circumstellar dust?

(no reddening / Na ID absorption…)

  • 2. ”IR-catastrophe”?

(Fransson&Jerkstrand 2015)

  • 3. Bound remnant?

Optically thick wind blown from partially disrupted progenitor WD?

The IR surprise from SN 2014dt

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  • Pushing the time frontier allow us to find SNe

as they happen (ZTF now on sky!)

  • UV follow-up and flash-spectroscopy probes

mass loss during the final year of stars lives (more robotic spectrographs coming up…)

  • SPIRITS survey finding lots of previously

missed transients!

  • IR probes mass loss histories thousands of

years prior to SN explosions

SUMMARY