light-echo spectrum revealed types of tycho brahes’s 1572 & cas a sne
DESCRIPTION
Light-Echo Spectrum revealed types of Tycho Brahes’s 1572 & Cas A SNe. Tomonori Usuda (SUBARU) Oliver Krause, Stephan M. Birkmann, Miwa Goto (MPIA), Takashi Hattori (Subaru Telescope), Masaomi Tanaka, Ken’ichi Nomoto (Univ. of Tokyo), George H. Rieke, Karl A. Misselt (Steward Observatory). - PowerPoint PPT PresentationTRANSCRIPT
Subaru Users Meeting (January 15, 2009)
Light-Echo Spectrum revealed types of Tycho Brahes’s 1572 & Cas A SNe
Cas ABlue ： X-ray (CXO)Green ： Optical (HST)Red ： Mid-IR (SST)
Tomonori Usuda (SUBARU)
Oliver Krause, Stephan M. Birkmann, Miwa Goto (MPIA), Takashi Hattori (Subaru Telescope),
Masaomi Tanaka, Ken’ichi Nomoto (Univ. of Tokyo),
George H. Rieke, Karl A. Misselt (Steward Observatory)
TychoBGY ： X-ray (CXO)Red ： Mid-IR (SST)White: Near-IR
Subaru Users Meeting (January 15, 2009)
Outline1. Review Galactic Supernova Remnants (SNRs) &
Historical Supernovae (SNe)
• Cassiopeia A (Cas A)
• Tycho Brahe’s SN 1572
2. Special Observation Tool: Light echo
3. Case 1: Cas A – Observation / Results
4. Case 2: Tycho – Observation / Results
5. Future plans & Conclusion
Subaru Users Meeting (January 15, 2009)
Designation Year Type
RCW86 185 II / Ia ?
G11.2-0.3 393 ?
Lupus 1006 Ia
Crab 1054 II
3C58 1181 ? II ?
Tycho 1572 Ia
Kepler 1604 Ia / Ib ?
Cas A 1680 ? Ib / Ic / II ?
G1.9+0.3 1870? ?
Review Galactic Supernova?
Kepler
G11.2
RCW86
Tycho Brahe
Crab
Cassiopeia A
G1.9
Subaru Users Meeting (January 15, 2009)
Cassiopeia A
• Second youngest SNR known in our Galaxy(cf. G1.9+0.3 discovered by CXO in 05/13/2008)
• Well known & studied SNR
• It might be appeared around 1680, however no historic records(e.g., SN1054: Crab by Teika Fujiwara 『 Meigetsuki 』 )
Q1: What kind of supernova explosion?
Q2: Why it was not witnessed in 17th century?
Subaru Users Meeting (January 15, 2009)
Tycho Brahes’s 1572 Supernova• Well known & studied SNR• Danish astronomer Tycho Brahe found very bright `new
star’ in the constellation of Cassiopeia on the evening of 11th of November in 1572. He had observed its brightness, color, and proper motion until March in 1574.
• In 20th century, the `new star’ = A supernova– Brightness & Color light curve ←→ Theoretical Model of SN
– X-ray observations → Spherical symmetry of metal abundance
– Radio etc. → No pulser
– Optical → Candidate of surviving binary companion of SN 1572
Q: Is SN 1572 really type Ia Supernova?
→ Classified by only optical spectrum``Astronomie Populaire” by Camille Flammarion (Paris, 1884)
Subaru Users Meeting (January 15, 2009)
How we can solve the mysteries on the past?!
Light Echo can go back to the past rewind time
Subaru Users Meeting (January 15, 2009)
Light echoes – Rewinding time to historic SN explosions
Echo (sound)2800 ft
(850m)
5 seconds
Subaru Users Meeting (January 15, 2009)
Light echoes – Rewinding time to historic SN explosions
Blue : Light of SN explosion arrived at Earth in 1572.
Red : Scattered-light echo by dust arrives now.
Subaru Users Meeting (January 15, 2009)
"As Professor J.H. Oort has pointed out to us, the illumination of surrounding clouds might become a spectacular phenomenon in the case of galactic supernovae. The search for the illumination of galactic clouds by past suspected supernovae such as Tycho's star and the stars which gave rise to the Crab Nebula and perhaps other nebulosities presents an interesting problem”.
By Zwicky Rev. Mod. Phys. 12, 66 (1940)
Light echoes – Rewinding time to historic SN explosions
Suntzeff
SN 1987A
Subaru Users Meeting (January 15, 2009)
However… Observation of Light echo is very difficult.
•Very Faint (Light echo became fainter and fainter day by day)
→ Even though can detect light echo, difficult to take its spectrum
•When? Where? How bright?
→ Just wait and Searching
Light echoes – Rewinding time to historic SN explosions
Suntzeff
SN 1987A
Echo geometry
Dust cloud
SN
Subaru Users Meeting (January 15, 2009)
Observations• When? Where? How bright?
→ Monitoring and ToO (Target of Opportunity)
→ International collaborations with MPIA
• Calar Alto 2.2m & 3.5m + Wide Optical Camera
PI: Oliver Krause (MPIA)
→ Monitoring & Looking for optical light echo
• Subaru Telescope 8.3m + FOCAS
PI: Tomonori Usuda (Subaru/NAOJ)
→ Imaging: Re-confirmation of light echo
Spectroscopy: Take its optical spectrum
Subaru Users Meeting (January 15, 2009)
Case 1: Cassiopeia A
Subaru Users Meeting (January 15, 2009)
October 9, 2007
Spectro-scopy
Associated scattered light echo by Calar Alto 2.2m & SUBARU 8.2m
SUBARU+
FOCAS
Detect optical light echo!
R = 23.4 mag / arcsec2
Subaru Users Meeting (January 15, 2009)
•=2.4nm (476~989 nm) / Av=3.1 mag•Exp time=5.5 hours
Results: Spectroscopy
•Spectral features of Supernovae•Broad line width (17,000 km/s) / P-Cygni profile•Strong H & He emission lines
He I Hα He IWent back in time to detect light that originally arrived at Earth more
than 330 years ago.
Subaru Users Meeting (January 15, 2009)
ResultsType sub-type Spectral Feature
I
Ia•No Hydrogen lines•Strong Si lines•Remarkable Fe lines in later phases
Ib•No Hydrogen lines•Remarkable He lines in max period•Weak Si lines / No Fe lines
Ic•No H & He lines•Weak Si lines / No Fe lines
IIII
•Strong H lines•Light curve → II-P-type (plateau), II-L-type (linear), II-n-type (narrow)
IIb•Visible H lines•Remarkable He lines
Subaru Users Meeting (January 15, 2009)
Comparison with the proto-typicaltype IIb SN 1993J
Subaru Users Meeting (January 15, 2009)
ResultsType sub-type Spectral Feature
I
Ia•No Hydrogen lines•Strong Si lines•Remarkable Fe lines in later phases
Ib•No Hydrogen lines•Remarkable He lines in max period•Weak Si lines / No Fe lines
Ic•No H & He lines•Weak Si lines / No Fe lines
IIII
•Strong H lines•Light curve → II-P-type (plateau), II-L-type (linear), II-n-type (narrow)
IIb•Visible H lines•Remarkable He lines
Subaru Users Meeting (January 15, 2009)
Cas A was a type IIb SN & Red Supergiant (13-20 Solar Mass) as progenitor star
Comparison with the proto-typicaltype IIb SN 1993J
Subaru Users Meeting (January 15, 2009)
Case 2: Tycho
Subaru Users Meeting (January 15, 2009)
N
E
30”
Results: Imaging
a: Calar Alto 2.2mb: Subaru ＋ FOCAS
Back box: Previous light echo position in 2006
Red+ mark: Brightest position (R=23.5 mag)
→ Slit position (2.8”x2.0”) for spectroscopy by FOCAS
→ Subtraction of sky & nebulosity lines
Center of SNR
Center of SNR
Slit positionShift
Subaru Users Meeting (January 15, 2009)
Results: Spectroscopy
•Remarkable spectral features of Supernovae•Broad line width (9,000~12,000 km/s)•No H & He lines•Strong absorption lines of Si and Fe
Hα
Si
He
Optical spectrum of the light that originally arrived at Earth in 1572
•=2.4nm (380~920 nm) / Av=2.4 mag•Exp time=2.5 hours (Red) + 1.5 hours (Blue)
Subaru Users Meeting (January 15, 2009)
ResultsType sub-type Spectral Feature
I
Ia•No Hydrogen lines•Strong Si lines•Remarkable Fe lines in later phases
Ib•No Hydrogen lines•Remarkable He lines in max period•Weak Si lines / No Fe lines
Ic•No H & He lines•Weak Si lines / No Fe lines
IIII
•Strong H lines•Light curve → II-P-type (plateau), II-L-type (linear), II-n-type (narrow)
IIb•Visible H lines•Remarkable He lines
Subaru Users Meeting (January 15, 2009)
Results: Spectroscopy
•Spectral features of Supernovae•Broad line width (9,000~12,000 km/s)•No H & He lines•Strong absorption lines of Si and Fe
→ Type Ia Supernova
Hα
Si
He
Subaru Users Meeting (January 15, 2009)
ResultsType sub-type Spectral Feature
I
Ia•No Hydrogen lines•Strong Si lines•Remarkable Fe lines in later phases
Ib•No Hydrogen lines•Remarkable He lines in max period•Weak Si lines / No Fe lines
Ic•No H & He lines•Weak Si lines / No Fe lines
IIII
•Strong H lines•Light curve → II-P-type (plateau), II-L-type (linear), II-n-type (narrow)
IIb•Visible H lines•Remarkable He lines
Subaru Users Meeting (January 15, 2009)
Type Ia SN = Cosmological distance indicator
→ Discovery of the accelerated expansion of Universe
Luminosity is NOT uniform!
Various type Ia Supernova
Normal
Type Ia SN OverluminousSubluminous
Reason why its variety of luminosity?→ Accurate cosmological distance indicator?
SiCa
FeNi
SiCa
FeNi
SiCa
FeNi
Subaru Users Meeting (January 15, 2009)
Results: Spectroscopy
Overluminous type Ia
Normal type Ia
Subluminous type Ia
Tycho was normal type Ia SN
Subaru Users Meeting (January 15, 2009)
Unique opportunity to test theories of SN Explosion mechanism
d=100 Mpc d = 3.8 kpc
10 arcmin
SNe in extra-galaxies Tycho’s SNR
Point source
Subaru Users Meeting (January 15, 2009)
Spatial Resolved Investigation
HighVelocity Ca II
Subaru Users Meeting (January 15, 2009)
Conclusions• For the first time, spectra of historical Galactic supernovae
(Cas A & Tycho) have been secured.
• Cas A: Type IIb SN & Red Supergiant (13~20 Mo)
• Why Cas A was not witnessed in 17th century
Type IIb SN fade away quickly, poor weather of several days, higher extinction (Av~8), peak brightness (~3 mag)
• Tycho: Normal type Ia SN & d=3.4kpc (cf. 2.3~2.8 kpc)
• Light echoes at different position angles from the source
→3D aspect
→ Spatial structure of SN outburst mechanism
Subaru Users Meeting (January 15, 2009)
Mahalo !