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ISDT ReportTime-domain Science
Masaomi Tanaka(National Astronomical Observatory of Japan)
* at this form
G.C. Anupama (IIA) (Convener) Manjari Bagchi (Tata Institute) Varun Bhalerao (IUCAA)U.S. Kamath (IIA)Lucas Macri (Texas A&M)Keiichi Maeda (Kyoto)Shashi Pandey (ARIES)Enrico Ramirez-Ruiz (UCSC)
Warren Skidmore (TMT) (Chapter editor)Masaomi Tanaka (NAOJ) (Convener)Nozomu Tominaga (Konan)Lingzhi Wang (NAOC)Xiaofeng Wang (Tsinghua)Chao Wu (NAOC)Xufeng Wu (PMO)
ISDT time-domain group(15 members)
Update of Detailed Science Case
Thirty Meter Telescope
Detailed Science Case: 2007
TMT Science Advisory Committee
1. Introduction2. Overview3. Fundamental physics and cosmology4. The early Universe5. Galaxy formation and
the intergalactic medium
6. Extragalactic supermassive black holes7. Exploration of nearby galaxies8. The formation of stars and planets9. Exoplanets10. Our solar system
No section for time-domain science
Time-domain science??
Supernovae
GRBs
AGNs
Planet transit
YSOs
Microlensing
Asteroids
Cataclysmic variable
Tidal disruption
Asteroid occultation
Pulsar
RR LyraeCepheids...
Stellar pulsation
Luminous blue variable
Eclipsing binary
TMT.PSC.TEC.07.007.DRF02 PAGE VI
DETAILED SCIENCE CASE: 2014 July 13, 2014 4.16! Star cluster formation and evolution and their environmental dependence ...................................... 34!4.17! Resolved stellar populations as tracers of galaxy evolution .............................................................. 36!4.18! Reconstructing the star formation histories of nearby galaxies ......................................................... 38!4.19! The time-resolved history of the galaxies in the Local Volume: the TMT era ................................... 42!4.20! LSB and BCD galaxies study with TMT ............................................................................................. 43!4.21! Resolving Extreme Star Formation Environments in Luminous Infrared Galaxies at Low Redshift ........................................................................................................................................................... 46!4.22! Kinematics of star forming galaxies at z = 2 – 3 ................................................................................. 48!4.23! References .......................................................................................................................................... 49!
5.! TIME-DOMAIN SCIENCE 53!5.1! Overview ................................................................................................................................................ 53!5.2! Understanding the Nature of Type Ia Supernovae .............................................................................. 54!
5.2.1! Characterizing high-z Type Ia Supernovae: Towards a Better Standard Candle ........................ 54!5.2.2! Unveiling Explosion Mechanism of Type Ia Supernovae ............................................................. 55!
5.3! Identifying Shock Breakout of Core-Collapse Supernovae .................................................................. 56!5.4! Tracing high-z Universe with Supernovae ............................................................................................ 57!5.5! Hunt for Progenitor Systems of Supernovae ........................................................................................ 58!
5.5.1! Detecting Progenitor and Companion of Supernovae .................................................................. 58!5.5.2! Characterizing Circumstellar environment around Supernovae ................................................... 59!5.5.3! Probing the Final Stages of Massive Star Evolution: LBVs and Supernova Impostors ............... 60!
5.6! Identification of Gravitational-Wave Sources ....................................................................................... 60!5.7! Understanding Progenitors of Gamma-ray Bursts: Connection to Supernovae and Kilonovae ......... 61!5.8! Probing High-z Universe with Gamma-ray Bursts ............................................................................... 62!5.9! Studying Tidal Disruption Events and Supermassive Black Holes ...................................................... 63!5.10! Cataclysmic Variables. ........................................................................................................................ 64!
5.10.1! Investigating the Dissipative Process in Cataclysmic Variable Accretion Discs and Disc Evolution During Outburst Cycles .............................................................................................................. 65!5.10.2! Revealing Geometry and Populations of Classical Novae ......................................................... 66!
5.11! Companions of Binary Radio Pulsars ................................................................................................. 67!5.12! Improving the Hubble Constant and Measuring Extragalactic Distances ......................................... 68!5.13! Summary of Requirements ................................................................................................................. 69!5.14! References .......................................................................................................................................... 72!
6.! FUNDAMENTAL PHYSICS AND COSMOLOGY 76!6.1! The nature of dark matter ..................................................................................................................... 76!
6.1.1! Dwarf galaxy radial mass profiles .................................................................................................. 76!6.1.2! Dark Matter Substructure ............................................................................................................... 78!6.1.3! Dark Matter self-interaction cross-section ..................................................................................... 79!6.1.4! Baryonic power spectrum .............................................................................................................. 79!6.1.5! Dark energy and modified gravity .................................................................................................. 81!6.1.6! Time-Delay cosmography .............................................................................................................. 83!6.1.7! Cosmology from clusters of Galaxies ............................................................................................ 83!6.1.8! Tests of general relativity ............................................................................................................... 84!
6.2! Physics of extreme objects – Neutron Stars ........................................................................................ 85!6.3! Variation of fundamental physical constants ........................................................................................ 86!6.4! References ............................................................................................................................................ 87!
Type Ia SN
Core-collapse SN
SN progenitor
GW sources
GRBs
Tidal disruption
CVs
Pulsars
Cepheids
DSC 2014
Time-domain science??
Target of opportunityobservations
Time-resolved observations
Monitoring observations
Time-domain science??
Type Ia SN
Core-collapse SN
GW sources
GRBs
Tidal disruption
Classical novaeRapid response
(telescope, operation)
CVs, X-ray binary(accretion disk) Pulsars
Rapid sampling(instruments)
Cepheids RR LyraeBinaries AGNs
Flexibletime allocation
Frontier: Short timescale transients
4 S. R. KULKARNI CALTECH OPTICAL OBSERVATORIES PASADENA, CALIFORNIA 91125, USA
The sources of interest to these facilities are connected to spectacular explosions. How-ever, the horizon (radius of detectability), either for reasons of optical depth (GZK cuto↵;�� ! e±) or sensitivity, is limited to the Local Universe (say, distance . 100Mpc). Un-fortunately, these facilities provide relatively poor localization. The study of explosions inthe Local Universe is thus critical for two reasons: (1) sifting through the torrent of falsepositives (because the expected rates of sources of interest is a tiny fraction of the knowntransients) and (2) improving the localization via low energy observations (which usuallymeans optical). In Figure 2 we display the phase space informed by theoretical considera-tions and speculations. Based on the history of our subject we should not be surprised tofind, say a decade from now, that we were not su�ciently imaginative.
Figure 2. Theoretical and physically plausible candidates are marked in theexplosive transient phase space. The original figure is from Rau et al. (2009).The updated figure (to show the unexplored sub-day phase space) is from theLSST Science Book (v2.0). Shock breakout is the one assured phenomenon on thesub-day timescales. Exotica include dirty fireballs, newly minted mini-blazars andorphan afterglows. With ZTF we aim to probe the sub-day phase space (see §5).
The clarity a↵orded by our singular focus – namely the exploration of the transientoptical sky – allowed us to optimize PTF for transient studies. Specifically, we undertakethe search for transients in a single band (R-band during most of the month and g bandduring the darkest period). As a result our target throughput is five times more relativeto multi-color surveys (e.g. PS-1, SkyMapper).
Given the ease with which transients (of all sorts) can be detected, in most instances, thetransient without any additional information for classification does not represent a useful,let alone a meaningful, advance. It is useful here to make the clear detection betweendetection7 and discovery.8 Thus the burden for discovery is considerable since for most
7 By which I mean that a transient has been identified with a reliable degree of certainty.8By which I mean that the astronomer has a useful idea of the nature of the transient. At the very
minimum we should know if the source is Galactic or extra-galactic. At the next level, it would be useful
Figure from LSST Science Book(after PTF collaboration, Rau+09, Kasliwal+,Kulkarni+)
Nova
Supernovae
Theoretically expected
Swift!
High cadence
ROTSE
HST
SNLSPan-STARRS
SDSS
PTFPTF
16
18
20
22
24
26
28 0.01 0.1 1 10 100
Mag
nitu
de
Cadence (days)
Deep
KISS
LSST2022-
iPTF
SubaruHSC
SubaruHSC
First transient survey with Subaru/HSC (2014 July 2-3 UT)
New imageSubtracted image
1.5 deg
Tominaga et al.
Ref New Sub Ref New Sub
http://tpweb2.phys.konan-u.ac.jp/~tominaga/HSC-SN/
The moment of supernova explosion
L12 TOMINAGA ET AL. Vol. 705
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1
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5 NUV
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1
2
3
4
5
-20 -10 0 10 20 30Days since the peak (observer frame) [Days]
Flux
[10-3
2 W m
-2 H
z-1]
FUV
Figure 2. Comparison between the NUV (top) and FUV (bottom) observations(points, SNLS-04D2dc; Schawinski et al. 2008) and the SN IIP model withoutthe host galaxy extinction (dot-dashed line) and reddened for the host galaxyextinction with EB−V,host = 0.06 mag (dashed line), 0.14 mag (solid line), and0.22 mag (dotted line).
the values are slightly different from Schawinski et al. (2008),the total extinction integrated over each band depends on theintrinsic spectrum and varies with time as the spectrum changes.The variations of extinction in the UV bands are relatively large;for example, ∼0.3 mag in the FUV band and ∼0.1 mag in theNUV band from t = 0 to 20 days for the SN IIP model withMZAMS = 20 M⊙ and E = 1.2 × 1051 erg.
Because of the large uncertainty, we assume several valuesfor the color excess of the host galaxy as follows: EB−V,host =0 mag referring to the case of no extinction in the hostgalaxy, EB−V,host = 0.06 mag giving half of the standardextinction in the NUV band, EB−V,host = 0.14 mag being thestandard extinction, and EB−V,host = 0.22 mag giving doubleof the standard extinction in the NUV band, which lead to(ANUV, AFUV) = (0.18 mag, 0.15 mag), (0.75 mag, 1.10 mag),(1.51 mag, 2.38 mag), and (2.27 mag, 3.65 mag), respectively.Here, we assume the SMC reddening law for the host galaxy.
Figure 2 shows comparisons of UV LCs with the model withMZAMS = 20 M⊙ and E = 1.2 × 1051 erg. The model LCs areconsistent with the observations within the uncertainty, whilethey are slightly fainter than the observations for EB−V,host =0.14 mag. The explosion energy of SNLS-04D2dc is consistentwith the canonical value of the explosion energies of core-collapse SNe (e.g., SN 1987A: E = (1.1 ± 0.3) × 1051 erg;Blinnikov et al. 2000). Although the 56Ni–56Co radioactivedecay does not contribute to the shock breakout, we expedientlyassume a canonical 56Ni ejection without mixing to the envelope(the ejected 56Ni mass M(56Ni) = 0.07 M⊙; e.g., SN 1987A:Blinnikov et al. 2000), and thus Mej = 16.9 M⊙ to yield0.07 M⊙ of 56Ni.
The second peak in the NUV LC at t ∼ 3 days is reproducedby the model and explained by the shift of the peak wavelength
2
4
6
8
10
0 20 40 60 80 100
Pho
tosp
heric
vel
ocity
[103 k
m]
Days since the peak (rest frame) [Days]
104
105
Col
or te
mpe
ratu
re [K
]
105
0 0.2 0.4 0.6
1042
1043
1044
1045
Bol
omet
ric lu
min
osity
[erg
s-1
]
1043
1044
1045
0 0.2 0.4 0.6
Figure 3. Bolometric LC (top), color temperature evolution (middle), andphotospheric velocity evolution (bottom) of the SN IIP model (lines). The insetsin the top and middle panels enlarge the phase of shock breakout.
as Schawinski et al. (2008) and Gezari et al. (2008) suggested.The bolometric LC and the evolution of color temperature areshown in Figure 3. Figure 3 also shows the velocity evolutionof photosphere defined as a position where the radiation andgas are decoupled. Although the bolometric luminosity declinesmonotonically after the shock breakout, the radiation energy inthe NUV band increases with time because the peak wavelengthshifts long (Figure 1). After the NUV second peak, the color tem-perature decreases further and the peak wavelength shifts to theoptical bands. The shift is caused by not only the decreasing tem-perature of the SN ejecta, but also an enhancement of the metalabsorption lines due to the low temperature. As a result, the UVluminosity declines monotonically after the NUV second peak.The model also predicts a second peak in the FUV band but thebrightening is obscured because of the low signal-to-noise ratio.
3.2. Optical Light Curves at Plateau Stage
Thanks to the multigroup radiation hydrodynamics calcula-tions, subsequent evolutions of multicolor lights are obtainedand compared with the SNLS optical observations. Figure 4shows comparisons of the g-, r-, i-, and z-band LCs. Here, weadopt EB−V,host = 0.14 mag and the SMC reddening law forthe host galaxy. The total extinction at the effective wavelengthsof the g-, r-, i-, and z-band filters of the MegaPrime/MegaCamon CFHT are as large as Ag = 0.64 mag, Ar = 0.47 mag,Ai = 0.36 mag, and Az = 0.28 mag, respectively.
As SED peaks in the g-band at t ∼ 20 days (Figure 1),the g-band LC peaks at t ∼ 20 days. After this epoch, the
L12 TOMINAGA ET AL. Vol. 705
-2
-1
0
1
2
3
4
5 NUV
-2
-1
0
1
2
3
4
5
-20 -10 0 10 20 30Days since the peak (observer frame) [Days]
Flu
x [1
0-32 W
m-2
Hz-1
]
FUV
Figure 2. Comparison between the NUV (top) and FUV (bottom) observations(points, SNLS-04D2dc; Schawinski et al. 2008) and the SN IIP model withoutthe host galaxy extinction (dot-dashed line) and reddened for the host galaxyextinction with EB−V,host = 0.06 mag (dashed line), 0.14 mag (solid line), and0.22 mag (dotted line).
the values are slightly different from Schawinski et al. (2008),the total extinction integrated over each band depends on theintrinsic spectrum and varies with time as the spectrum changes.The variations of extinction in the UV bands are relatively large;for example, ∼0.3 mag in the FUV band and ∼0.1 mag in theNUV band from t = 0 to 20 days for the SN IIP model withMZAMS = 20 M⊙ and E = 1.2 × 1051 erg.
Because of the large uncertainty, we assume several valuesfor the color excess of the host galaxy as follows: EB−V,host =0 mag referring to the case of no extinction in the hostgalaxy, EB−V,host = 0.06 mag giving half of the standardextinction in the NUV band, EB−V,host = 0.14 mag being thestandard extinction, and EB−V,host = 0.22 mag giving doubleof the standard extinction in the NUV band, which lead to(ANUV, AFUV) = (0.18 mag, 0.15 mag), (0.75 mag, 1.10 mag),(1.51 mag, 2.38 mag), and (2.27 mag, 3.65 mag), respectively.Here, we assume the SMC reddening law for the host galaxy.
Figure 2 shows comparisons of UV LCs with the model withMZAMS = 20 M⊙ and E = 1.2 × 1051 erg. The model LCs areconsistent with the observations within the uncertainty, whilethey are slightly fainter than the observations for EB−V,host =0.14 mag. The explosion energy of SNLS-04D2dc is consistentwith the canonical value of the explosion energies of core-collapse SNe (e.g., SN 1987A: E = (1.1 ± 0.3) × 1051 erg;Blinnikov et al. 2000). Although the 56Ni–56Co radioactivedecay does not contribute to the shock breakout, we expedientlyassume a canonical 56Ni ejection without mixing to the envelope(the ejected 56Ni mass M(56Ni) = 0.07 M⊙; e.g., SN 1987A:Blinnikov et al. 2000), and thus Mej = 16.9 M⊙ to yield0.07 M⊙ of 56Ni.
The second peak in the NUV LC at t ∼ 3 days is reproducedby the model and explained by the shift of the peak wavelength
2
4
6
8
10
0 20 40 60 80 100
Pho
tosp
heric
vel
ocity
[103 k
m]
Days since the peak (rest frame) [Days]
104
105
Col
or te
mpe
ratu
re [K
]
105
0 0.2 0.4 0.6
1042
1043
1044
1045
Bol
omet
ric lu
min
osity
[erg
s-1
]
1043
1044
1045
0 0.2 0.4 0.6
Figure 3. Bolometric LC (top), color temperature evolution (middle), andphotospheric velocity evolution (bottom) of the SN IIP model (lines). The insetsin the top and middle panels enlarge the phase of shock breakout.
as Schawinski et al. (2008) and Gezari et al. (2008) suggested.The bolometric LC and the evolution of color temperature areshown in Figure 3. Figure 3 also shows the velocity evolutionof photosphere defined as a position where the radiation andgas are decoupled. Although the bolometric luminosity declinesmonotonically after the shock breakout, the radiation energy inthe NUV band increases with time because the peak wavelengthshifts long (Figure 1). After the NUV second peak, the color tem-perature decreases further and the peak wavelength shifts to theoptical bands. The shift is caused by not only the decreasing tem-perature of the SN ejecta, but also an enhancement of the metalabsorption lines due to the low temperature. As a result, the UVluminosity declines monotonically after the NUV second peak.The model also predicts a second peak in the FUV band but thebrightening is obscured because of the low signal-to-noise ratio.
3.2. Optical Light Curves at Plateau Stage
Thanks to the multigroup radiation hydrodynamics calcula-tions, subsequent evolutions of multicolor lights are obtainedand compared with the SNLS optical observations. Figure 4shows comparisons of the g-, r-, i-, and z-band LCs. Here, weadopt EB−V,host = 0.14 mag and the SMC reddening law forthe host galaxy. The total extinction at the effective wavelengthsof the g-, r-, i-, and z-band filters of the MegaPrime/MegaCamon CFHT are as large as Ag = 0.64 mag, Ar = 0.47 mag,Ai = 0.36 mag, and Az = 0.28 mag, respectively.
As SED peaks in the g-band at t ∼ 20 days (Figure 1),the g-band LC peaks at t ∼ 20 days. After this epoch, the
Tominaga+09
L12 TOMINAGA ET AL. Vol. 705
-2
-1
0
1
2
3
4
5 NUV
-2
-1
0
1
2
3
4
5
-20 -10 0 10 20 30Days since the peak (observer frame) [Days]
Flux
[10-3
2 W m
-2 H
z-1]
FUV
Figure 2. Comparison between the NUV (top) and FUV (bottom) observations(points, SNLS-04D2dc; Schawinski et al. 2008) and the SN IIP model withoutthe host galaxy extinction (dot-dashed line) and reddened for the host galaxyextinction with EB−V,host = 0.06 mag (dashed line), 0.14 mag (solid line), and0.22 mag (dotted line).
the values are slightly different from Schawinski et al. (2008),the total extinction integrated over each band depends on theintrinsic spectrum and varies with time as the spectrum changes.The variations of extinction in the UV bands are relatively large;for example, ∼0.3 mag in the FUV band and ∼0.1 mag in theNUV band from t = 0 to 20 days for the SN IIP model withMZAMS = 20 M⊙ and E = 1.2 × 1051 erg.
Because of the large uncertainty, we assume several valuesfor the color excess of the host galaxy as follows: EB−V,host =0 mag referring to the case of no extinction in the hostgalaxy, EB−V,host = 0.06 mag giving half of the standardextinction in the NUV band, EB−V,host = 0.14 mag being thestandard extinction, and EB−V,host = 0.22 mag giving doubleof the standard extinction in the NUV band, which lead to(ANUV, AFUV) = (0.18 mag, 0.15 mag), (0.75 mag, 1.10 mag),(1.51 mag, 2.38 mag), and (2.27 mag, 3.65 mag), respectively.Here, we assume the SMC reddening law for the host galaxy.
Figure 2 shows comparisons of UV LCs with the model withMZAMS = 20 M⊙ and E = 1.2 × 1051 erg. The model LCs areconsistent with the observations within the uncertainty, whilethey are slightly fainter than the observations for EB−V,host =0.14 mag. The explosion energy of SNLS-04D2dc is consistentwith the canonical value of the explosion energies of core-collapse SNe (e.g., SN 1987A: E = (1.1 ± 0.3) × 1051 erg;Blinnikov et al. 2000). Although the 56Ni–56Co radioactivedecay does not contribute to the shock breakout, we expedientlyassume a canonical 56Ni ejection without mixing to the envelope(the ejected 56Ni mass M(56Ni) = 0.07 M⊙; e.g., SN 1987A:Blinnikov et al. 2000), and thus Mej = 16.9 M⊙ to yield0.07 M⊙ of 56Ni.
The second peak in the NUV LC at t ∼ 3 days is reproducedby the model and explained by the shift of the peak wavelength
2
4
6
8
10
0 20 40 60 80 100
Pho
tosp
heric
vel
ocity
[103 k
m]
Days since the peak (rest frame) [Days]
104
105
Col
or te
mpe
ratu
re [K
]
105
0 0.2 0.4 0.6
1042
1043
1044
1045
Bol
omet
ric lu
min
osity
[erg
s-1
]
1043
1044
1045
0 0.2 0.4 0.6
Figure 3. Bolometric LC (top), color temperature evolution (middle), andphotospheric velocity evolution (bottom) of the SN IIP model (lines). The insetsin the top and middle panels enlarge the phase of shock breakout.
as Schawinski et al. (2008) and Gezari et al. (2008) suggested.The bolometric LC and the evolution of color temperature areshown in Figure 3. Figure 3 also shows the velocity evolutionof photosphere defined as a position where the radiation andgas are decoupled. Although the bolometric luminosity declinesmonotonically after the shock breakout, the radiation energy inthe NUV band increases with time because the peak wavelengthshifts long (Figure 1). After the NUV second peak, the color tem-perature decreases further and the peak wavelength shifts to theoptical bands. The shift is caused by not only the decreasing tem-perature of the SN ejecta, but also an enhancement of the metalabsorption lines due to the low temperature. As a result, the UVluminosity declines monotonically after the NUV second peak.The model also predicts a second peak in the FUV band but thebrightening is obscured because of the low signal-to-noise ratio.
3.2. Optical Light Curves at Plateau Stage
Thanks to the multigroup radiation hydrodynamics calcula-tions, subsequent evolutions of multicolor lights are obtainedand compared with the SNLS optical observations. Figure 4shows comparisons of the g-, r-, i-, and z-band LCs. Here, weadopt EB−V,host = 0.14 mag and the SMC reddening law forthe host galaxy. The total extinction at the effective wavelengthsof the g-, r-, i-, and z-band filters of the MegaPrime/MegaCamon CFHT are as large as Ag = 0.64 mag, Ar = 0.47 mag,Ai = 0.36 mag, and Az = 0.28 mag, respectively.
As SED peaks in the g-band at t ∼ 20 days (Figure 1),the g-band LC peaks at t ∼ 20 days. After this epoch, the
Days
2 hr !!
supernovaeat z~2
Deep, high-cadence
survey (g = 27 mag)
New window to study supernovae(SFRs, SN progenitor, SN kinetic energy)
TMT/MOBIE spectroscopy within 30 min
Paradigm shift in 2020s: Gravitational waves
NS-NS merger with 200 Mpc
2017 - - Advanced LIGO (US)- Advanced Virgo (Europe)- KAGRA (Japan)
“Multi-messenger” astronomy
- Compact binaries- Properties of dense matter- r-process nucleosynthesis- ...
KAGRA
Virgo
LIGO
1 deg
SDSS
1 deg
GW alert errore.g. 6 deg x 6 deg
(not box shape in reality)
No electromagnetic counterpartNo gravitational wave astronomy
EM transient searchw/ wide-field telescope
(e.g., LSST, HSC)
GW detection
Source identification(TMT)
SubaruHSC
1.5 deg
LSST3.5 deg
1
2
3
4
5
6
5000 10000 15000 20000
Log
flux
(Fh)
+ c
onst
ant
Wavelength (A)
1.5 days5.0 days10.0 days
1
2
3
4
5
6
5000 10000 15000 20000
Log
flux
(Fh)
+ c
onst
ant
Wavelength (A)
1.5 days5.0 days10.0 days
Type Ia
1
2
3
4
5
6
5000 10000 15000 20000
Log
flux
(Fh)
+ c
onst
ant
Wavelength (A)
1.5 days5.0 days10.0 daysLGRB-SN
Optical/NIR spectroscopy with MOBIE+IRIS~25 mag for 5 days @ 200 Mpc( > 100 SNe within localization area)NS merger = extremely broad-line, red spectra
Smoking gun: spectroscopic identification
MT & Hotokezaka 13
RV I J HBU
- Metal abundances- HI column density- Ly alpha escape fraction- Intervening systems
GRB as a probe of high-z Universe(by Antonino Cucchiara yesterday)
Chornock+13
Need more interactionwith other ISDTs
TMT/IRIS can reach z=8-10!
TMT.PSC.TEC.07.007.DRF02 PAGE 69 OF 154
DETAILED SCIENCE CASE: 2014 July 13, 2014 TMT could greatly improve the near-infrared photometry of Cepheids already discovered with the Hubble Space Telescope in a dozen nearby hosts of type Ia supernovae (D < 50 Mpc Riess et al. 2011). The current studies are limited by crowding due to the angular resolution of HST and the coarse sampling provided by WFC3/IR, yielding Period-Luminosity relations with dispersions 3× larger than the intrinsic width. Diffraction-limited images with TMT/IRIS will provide a > 10× increase in angular resolution and a 25× finer pixel scale, effectively removing any biases due to crowding and yielding a 3× improvement in distance uncertainty. Thanks to the large collection area of TMT, S/N = 50 photometry can be obtained in less than 120s (Japan TMT ETC) for any object of interest (the faintest target would be a 20-day Cepheid at 50 Mpc, with K = 26.8 mag). Several neighboring fields (within 2 arc minutes of each other) could be observed in quick succession (the AO system has a requirement for a <5 second set up for moves up to 30 arc seconds, see TMT ORD). Once the JWST mission is completed, and in the absence of any comparable space-based assets, TMT will play a unique role in Extragalactic Distance Scale work. Beyond the determination of the Hubble constant, precise extragalactic distances have many useful applications; one example is the accurate calibration of the relation between bulge luminosity and black hole mass, which cannot be performed using samples in the Hubble flow. Near-infrared AO imaging with TMT/IRIS will greatly help to set Extragalactic distances up to and beyond 10 Mpc, using either RR Lyrae (Pcyc~0.5 day) out to D ~1 Mpc (requiring ten ~1hr exposures) or Cepheids out to the Coma cluster (D = 100 Mpc, requiring 1.5 hours of telescope time per integration and 10 observations over several months) for late-type systems.
5.13 SUMMARY OF REQUIREMENTS Table 5-1 summarizes requirements for the telescope and instruments to realize the science cases described in this chapter. Important functions, which are not available in the planned first-generation instruments, and thus are desirable for second-generation instruments, are written in Italic font. In order to maximize scientific outcome from time-domain astronomy, response time for ToO observations and sampling time for time-resolved observations are especially important. These requirements are also summarized in Figure 5.13-1.
Figure 5.13-1. Required ToO response time for different science cases
18
20
22
24
26
28100 101 102 103 104 105
10-3 10-2 10-1 100 101
Obs
erve
d M
agni
tude
Response time (min)
Response time (day)
1 hour 1 day1 min
High-z SNe Ia(NIR)
Low-z SNe Ia (opt)
SN shock breakout
(opt) High-z SNe(NIR)
SN CSM (opt, HR)
LBV(opt)
GW source (NIR)
GRB(NIR, HR)
TDE(opt)
Required response time
Response with 5 min
DSC 2014
Discussion (yesterday)
• System for ToO?
• Telescope/instruments become ready in 5 minUnique capability of TMT
• Human judge can easily take more time
• To maximize the scientific outcome of TMT:
• Ideally need automated system
• Prepare templates for observing modes(so that observers can quickly select)
• Inter-partner ToO observations?
• => Key program
Another frontier: Time-resolved observations
TMT.PSC.TEC.07.007.DRF02 PAGE 65 OF 154
DETAILED SCIENCE CASE: 2014 July 13, 2014 5.10.1 Investigating the Dissipative Process in Cataclysmic Variable Accretion Discs and Disc Evolution During Outburst Cycles
Cataclysmic Variables display rapid variability on timescales from sub-second to hours due to a number of reasons; accretion onto the compact primary, interactions of disc and mass transfer stream and processes in the accretion disc itself (as modeled by Ribeiro & Diaz, 2008). The location of the source of the variability can be isolated by studying the velocity of the emission and in some systems by eclipse mapping. Combining the velocity and timing information from time resolved spectroscopy with the method of eclipse mapping and monitoring disc changes on a weekly basis will transform our understanding the processes occurring within CV accretion discs, particularly in systems whose discs display changes in state or have regular outbursts on timescales of months. For example, in rapid (72ms) spectroscopic observations of the non-eclipsing dwarf nova SS Cyg (with S/N~35), Skidmore et al. (2004) found short (2 to 3 minute) flares (see Figure 5.10-1) whose temporal and spectroscopic behavior were consistent with arising in the accretion disc and could be described with the Fireball model of Pearson et al. (2005). From broad band photometry Baptista & Bortoletto (2008) and Baptista et al. (2011) respectively derived the spatial distribution of flickering in the discs of the nova-like UU Aqr and the systematic changes in the flickering distribution across the disc through an outburst of the dwarf nova HT Cas when the disc collapsed. Time resolved optical spectrometry with MOBIE with R=4000, duration about 20 minutes centered on mid-eclipse and tsamp=50ms will give S/N~1000 in each resolution element for Mv~15 (calculated with TMT-J ETC). At this magnitude there are an order of 100 eclipsing CVs (http://www.mpa-garching.mpg.de/RKcat/cbcat) that show a range of different accretion disc behaviors, allowing the development of a comprehensive understanding of accretion disc physics that is impossible to obtain with existing facilities.
Figure 5.10-1. (left) Continuum light-curves of a small flare seen in the Dwarf Nova SS Cyg. Light curves cover 3590A to 3640A (dot-dashed), 4165A to 4285A (dashed), 5400A to 5600A (solid) and 7080A to 7560A (dotted). Large dots show the times at which spectra shown in Figure 5.10-1 (right)
were measured. Y axis scaling is normalized. (right) Spectra at times throughout the flare with the underlying static spectrum removed.
Warren Skidmore� 7/13/14 4:50 PMDeleted: Figure 5.10-1
Warren Skidmore� 7/13/14 4:50 PMDeleted: Figure 5.10-1
75 ms spectroscopic sampling for cataclysmic variables(also for X-ray binaries)
Skidmore et al. 2004
Required sampling timeTMT.PSC.TEC.07.007.DRF02 PAGE 70 OF 154
DETAILED SCIENCE CASE: 2014 July 13, 2014
Figure 5.13-2. Figure showing the ranges of sampling times during observations of rapidly variable objects. In some cases the objects are continuously variable or observations can be scheduled, in other cases rapid observations are needed to follow the early evolution of a transient object after a
rapid response ToO program has been initiated (see Figure 5.13-1).
Table 5-1. Summary of Requirements for Time-Domain Science.
Science Case
Response time
Sampling time1
Cadence Brightness (mag)
Observing mode
Notes
Evolution of SNe Ia (1.2.1)
3-10 days
- 3-10 days 24 (NIR) NIR spectroscopy
(R = 500)
Synergy with NIR surveys (Euclid/WFIR
ST)
Explosion mechanism
1 hr - 1 day
- 1hr initially,
26 (opt.) 23 (NIR)
Optical/NIR spectroscopy
Synergy with LSST
1 Sampling time relates to the integration and deadtime of individual exposures in sequences of time resolved observations that require fast detector readout schemes. If single observations that are repeated on longer timescales then this is captured in the Cadence and nothing is reported in
Sampling with 10 msec(100 Hz)
DSC 2014by Warren Skidmore
Discussion (yesterday)
• To fully utilize 30m aperture
• 10 ms sampling
• 80 % efficiency (= 20% dead time)
• Accurate, absolute time stamp (direct comparison with multi-wavelength data)
• Need only a small part of FOV
10 ms2 ms
10 ms2 ms
How many pixels?
exp read + α
exp read + α
t
FOV
Need input from instrument groups
Summary
• Time-domain science needs TMT
• 11 science cases in updated DSC
• Time-domain science in 2020s
• Synergy with LSST/HSC transient surveys
• Synergy with gravitational wave telescopes
• Time-resolved observations with 30m aperture
• Requirement from time-domain science
• Response within 5 min (=> telescope/operation)
• 10 msec sampling with >80% efficiency (=> instruments)Need more communication with instrument groups
• Key program <=> inter-partner ToO program?
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