11

Type 2 Supernova Type 2 Supernova

J. van der VeldeUniversity of Michigan2 April. 2007

Blue Giant star

22

After (only) 1 million yrs…..After (only) 1 million yrs…..

Shell supported by pressure of nuclear

fusion burning

33

Core Collapse (~ 1 sec)Core Collapse (~ 1 sec)

44

ReboundRebound

55

66

77

88

1055

neutrinos

99

1010

1111

You

Me

1212

The last two nearby ones were in 1604 and 1572The last two nearby ones were in 1604 and 1572

~ 30 light yrs diam.

1313

Which brings us to IMB….Which brings us to IMB….

170,000 years ago a large star, Sandulek, in the 170,000 years ago a large star, Sandulek, in the Large Magellanic Cloud, underwent gravitational Large Magellanic Cloud, underwent gravitational collapse, sending a 10-second wide pulse of collapse, sending a 10-second wide pulse of neutrinos out into the Universe. This pulse hit the neutrinos out into the Universe. This pulse hit the Earth on 23 February, 1987, around UT 04:00, Earth on 23 February, 1987, around UT 04:00, when 3X10**15 neutrinos went through the IMB when 3X10**15 neutrinos went through the IMB detector. detector.

Six months before, the detector had been upgraded Six months before, the detector had been upgraded to increase it's photocathode coverage by a factor to increase it's photocathode coverage by a factor of four. This gave it just enough sensitivity to of four. This gave it just enough sensitivity to record eight neutrino events. record eight neutrino events.

1414

IMBIMB

Supernova 1987aSupernova 1987a

A HistoryA History

Of Dumb Luck ?Of Dumb Luck ?

Or….Or….

IIntelligent ntelligent DDesignesign ??

1515

Tokyo, August 1978Tokyo, August 1978

The story begins here:The story begins here:

XIX th International Conference onXIX th International Conference on

High Energy PhysicsHigh Energy Physics

Actually it began 170,020 years ago Actually it began 170,020 years ago

in the Large Magelanic Cloud, when humans were stillin the Large Magelanic Cloud, when humans were still

gnawing on bones. They couldn’t even gnawing on bones. They couldn’t even talktalk let alone let alone

do powerpoint …….. do powerpoint ……..

Let’s listen in back then, using top-secretLet’s listen in back then, using top-secret

““Blue Cloud” technology……..Blue Cloud” technology……..

1616

G: Hairy creatures on Earth G: Hairy creatures on Earth are starting to show signs of are starting to show signs of intelligence. In 170,000 years intelligence. In 170,000 years they will have Proton Decay they will have Proton Decay

detectors.detectors.g: They’ll never find PDK, as g: They’ll never find PDK, as

you know.you know. Their detectors are 1000 Their detectors are 1000

times too small.times too small. But what can you expect?But what can you expect?

Their Their brainsbrains are not made are not made of Silicon. of Silicon.

They’re made of They’re made of meat!meat!

1717

G: Yes, too bad. Let’s G: Yes, too bad. Let’s be nice and send them be nice and send them

some supernova some supernova neutrinos to appease neutrinos to appease

their funding agencies.their funding agencies.

g: How about Sandulek g: How about Sandulek in the LMC?in the LMC?

G: go for it !G: go for it !

1818

Sandulek in the LMCSandulek in the LMC

1919

Jump ahead… August, 1978Jump ahead… August, 1978

The Tokyo conference was all a-buzz with The Tokyo conference was all a-buzz with GGrand rand UUnification nification TTheoriesheories

““Minimal” SUMinimal” SU5 5 was predicting a proton was predicting a proton lifetime of 10lifetime of 102929 years for the mode years for the mode

p ep e+ + ππ00

Planes leaving Tokyo were filled with strange Planes leaving Tokyo were filled with strange characters holding little books and making weird characters holding little books and making weird

scratches on paper napkins, like….scratches on paper napkins, like….

2020

6.02 X 106.02 X 102626 protons/Kg protons/Kg

This is not a small numberThis is not a small number

compared to 10compared to 102929 years years

Make that 6 X 10Make that 6 X 102929 protons/tonne protons/tonne

…… ……gives 6 decays per tonne per year!gives 6 decays per tonne per year!

Hmmm….that’s only a cubic meter of waterHmmm….that’s only a cubic meter of water

2121

Pre-HistoryPre-History1925, Hermann Weyl:1925, Hermann Weyl:

“ “ Why doesn’t P+e photons ?”Why doesn’t P+e photons ?”1938, E.C.G.Stueckelberg and (1949)E.P. 1938, E.C.G.Stueckelberg and (1949)E.P.

Wigner : Wigner :

““That’s easy there’s something called That’s easy there’s something called Baryon Number which is conserved !”Baryon Number which is conserved !”

2222

OK, but why not look?OK, but why not look?

1954, Reines, Cowan, and Goldhaber: 1954, Reines, Cowan, and Goldhaber:

t >10t >102222 years years (Phys Rev (Phys Rev 9696, 1157), 1157)

1960 Backenstoss et al. (Nuovo Cimento 1960 Backenstoss et al. (Nuovo Cimento 1616 749) 749)

tt > 10> 102626 yearsyears

1974, Reines and Crouch: (Phys Rev Lett 1974, Reines and Crouch: (Phys Rev Lett 3232 493) 493)

t > 10t > 103030 years (for modes with muon) years (for modes with muon)

2323

1978 Fall Flurry of Activity1978 Fall Flurry of Activity

Brookhaven, Irvine, Harvard, Imperial Brookhaven, Irvine, Harvard, Imperial College, Michigan, Oxford, Purdue, College, Michigan, Oxford, Purdue, Wisconsin….…Wisconsin….…

For IMB the dust settled in January ’79.For IMB the dust settled in January ’79.A meeting at Irvine signed up: A meeting at Irvine signed up: W. Kropp, J. Learned, R. March, F. Reines, J. Schultz,W. Kropp, J. Learned, R. March, F. Reines, J. Schultz,D. Sinclair, H. Sobel, L. Sulak, J. van der Velde.D. Sinclair, H. Sobel, L. Sulak, J. van der Velde.

M. Goldhaber was soon added and letters of support M. Goldhaber was soon added and letters of support were solicited from Glashow, Gell-Mann, Salam and were solicited from Glashow, Gell-Mann, Salam and Weinberg.Weinberg.

2424

3 Months Later….3 Months Later….

2525

2626

2727

Relegated to the appendix, a paragraph Relegated to the appendix, a paragraph about possible about possible supernova detection:supernova detection:

““While insensitive to neutrinos below about 50 While insensitive to neutrinos below about 50 MeV, [the detector] would give excellent data on MeV, [the detector] would give excellent data on the spectrum above this energy and perhaps the spectrum above this energy and perhaps (uniquely) indicate [the suprnova] source (uniquely) indicate [the suprnova] source direction.” direction.”

If their brains were made of Silicon they

would have put this up front,

not in an appendix

2828

Proposal Presentation,Washington, May 31, 1979Proposal Presentation,Washington, May 31, 1979

2929

“That was a motley crew….

I wonder if they’ll amount to anything ?”

3030

28 November ’79… Big Day!28 November ’79… Big Day!

Official approval from D.O.E.Official approval from D.O.E.Dosco machine starts diggingDosco machine starts digging

3131

3232

28 November ’79… Big Day!28 November ’79… Big Day!

Official approval from D.O.E.Official approval from D.O.E. Dosco machine starts diggingDosco machine starts digging 2400 five-inch PMT’s ordered from EMI2400 five-inch PMT’s ordered from EMI-------------------------------------------------------------------------------------------------------------------------------------- ……. . One year of salt dust, construction, One year of salt dust, construction, plumbing, and other grub workplumbing, and other grub work----------------------------------------------------------------------------------------------------------------------

September 1980…. September 1980…. Digging finished! Digging finished!

Schlegel Co. is engaged to install plastic linerSchlegel Co. is engaged to install plastic liner

3333

G: The neutrino pulse is fast approaching…What’s going on?g: IMB is funded but their PM tubes are too small. Their proposal said they would need an electronics upgrade to detect supernova neutrinos.Kamiokande is thinking much bigger tubes.

G: Good for them. They must know about Intelligent Design

Spring of ‘81Spring of ‘81

3434

One year (and $200K) later…One year (and $200K) later…

3535

3636

SeptemberSeptember

19811981

3737

Turn on the watahTurn on the watah

HankHank

3838

30 November: 10 ft of water, small leaks 30 November: 10 ft of water, small leaks developdevelop

Divers called in to patch themDivers called in to patch them

3939

December ‘81December ‘81

Cosmic ray muonCosmic ray muon

signals look goodsignals look good

in 10 ft of waterin 10 ft of water

Yes, it really works…. Nice and clean

4040

20 January 198220 January 1982

Water depth = 13 ft.Water depth = 13 ft.Larger leaks developLarger leaks develop

The pool is MT’dThe pool is MT’d

We need a better planWe need a better plan

Something smooth to support the liner against the Something smooth to support the liner against the water pressurewater pressure

Something that doesn’t dissolve salt !Something that doesn’t dissolve salt !

4141

The AnswerThe Answer

Use low density (Use low density (ρρ = 1) concrete = 1) concrete

Pour it in while filling with waterPour it in while filling with water

Do it in stages to let it hardenDo it in stages to let it harden

May, ’82May, ’82

Dan gives schedule: “Full by August” Dan gives schedule: “Full by August”

4242

May 1982May 1982

We have some time to think…We have some time to think…

Idea: (revival)Idea: (revival)How about installing that hardware which How about installing that hardware which

would possibly enable us to see a would possibly enable us to see a supernova explosion in our galaxy? supernova explosion in our galaxy?

4343

G: Hey, are those IMB characters

getting our messages?

The SN1987A neutrinos are

99.997% of the way there !

4444

Hmmmm…Hmmmm…

Bethe estimates Bethe estimates ≤ ≤ one SN /30 yearsone SN /30 years Essentially all of the signal would be Essentially all of the signal would be

below our thresholdbelow our threshold

Let’s put it on the Back BurnerLet’s put it on the Back Burner

G: Who is Bethe?

4545

July 31, 1982July 31, 1982

The pool is full: 70 ft, no leaks

Reports from Paris ICRC meeting:

Soudan-1, NUSEX, KGF are finding

“Candidates”

We start taking data (slowly)

4646

October 7, 1982October 7, 1982

10 million triggers 10 million triggers

20 contained events20 contained events

Any candidates for PDK ?Any candidates for PDK ?

4747

This one looks interestingThis one looks interesting

4848

• Check opening angleCheck opening angle

Opening angle = 135 deg(Should be 150-180)

4949

Hmmm….Hmmm….

Total energy ?Total energy ?

1230 MeV1230 MeV

(Should be (Should be ≤≤ 1100) 1100)

Muon decay ?Muon decay ?

5050

Slow time scale windowSlow time scale window

Clear evidence

for muon decay

Cancel that call to the NY Times

5151

January ‘83January ‘83

First public report:First public report:

80 days of live time80 days of live time

NoNo candidates for P e candidates for P e++ ππ00

t/b t/b ≥ 5 X 10≥ 5 X 103131 yr yr

5252

Spring of ’83Spring of ’83the theorists regroupthe theorists regroup……

““How about How about µµ++kk00 …… etc ?” …… etc ?”

May ’83…. Kamiokande taking dataMay ’83…. Kamiokande taking data

We need more light collection !We need more light collection !

G: Uhhhh…. No kidding !

5353

Pictures for Upgrade Proposal to D.O.E.Pictures for Upgrade Proposal to D.O.E.

Us Them !

5454

July ‘83July ‘83

Set limit on PDK to (Set limit on PDK to (µµ++ k k00 )… )… ≥ ≥ 10103131 yr yr

Set limits on Monopole Catalysis of PDKSet limits on Monopole Catalysis of PDK

5555

September ‘83 September ‘83 Upgrade proposal presented to D.O.E.Upgrade proposal presented to D.O.E.

8-inch Hamamatsu PMT’s imbedded in wave8-inch Hamamatsu PMT’s imbedded in waveshifter plates 4X light collection ($1.7 M)shifter plates 4X light collection ($1.7 M)

April ’84:April ’84: D.O.E. agrees to $1.5 M, spread D.O.E. agrees to $1.5 M, spread out over out over 3 years3 years. . We order 8-inch tubes We order 8-inch tubes from Hamamatsu.from Hamamatsu.

Meanwhile we are installing wave shifters Meanwhile we are installing wave shifters on our 5-inch tubes… = “IMB-2”on our 5-inch tubes… = “IMB-2”

(Still not much good for SN’s)(Still not much good for SN’s)

G: These people are running out of time !

5656

January ‘85January ‘85

““Big List” of limits on 34 Big List” of limits on 34

decay modes of nucleons published in PRL.decay modes of nucleons published in PRL.

Nine “candidates” could be various off-beat Nine “candidates” could be various off-beat modes, but all are consistent with neutrino modes, but all are consistent with neutrino

background, e.g…..background, e.g…..

5757

Event 663-1770Event 663-1770

This is a candidate for neutron decay into e+ π

-

But it could also be a cosmic ray neutrino interaction.

“The value of a candidate depends on his background” ……Maurice Goldhaber

5858

A tough time for theorists…

American Way, July, 1983

5959

Sept. 1986….IMB-3 is ready!Sept. 1986….IMB-3 is ready!

6060

October ‘86October ‘86

We now have four times theWe now have four times the

Light collection of IMB-1Light collection of IMB-1

At a collaboration meeting Eric Shumard revives (again) At a collaboration meeting Eric Shumard revives (again) the idea to upgrade our data acquisition system to the idea to upgrade our data acquisition system to

facilitate automatic supernova detection.facilitate automatic supernova detection.

Decision: Decision: No $$$, No time, No $$$, No time, No urgencyNo urgency

Rule #One: Listen to your graduate students !

6262

February 23, 1987February 23, 1987UT 02:30 UT 02:30

G: Neutrinos just passed Pluto What’s going on?

g: Every one is asleep.

A Few Months Later….

6363

UT 05:00UT 05:00

G: the neutrino pulse is just passing Saturn.

What gives at IMB?

g: Detector on auto…Nobody there,

no supernova alert system in place.

G: Punish them!

6464

UT 05:00:00.001UT 05:00:00.001

One of four HV power suppliesOne of four HV power supplies

shuts down at IMB.shuts down at IMB.

On-line data analysis system shuts down.On-line data analysis system shuts down.

Detector limps ahead with ¾ tubesDetector limps ahead with ¾ tubes

and raw data tapes onlyand raw data tapes only

Two hours later…….Two hours later…….

6565

UT 07:35:41UT 07:35:41

Thirty thousand trillion neutrinos Thirty thousand trillion neutrinos

pass through the IMB detectorpass through the IMB detector

Only 8 are left behindOnly 8 are left behind

6666

UT 7:35:41.4UT 7:35:41.4

6767

UT 7:35:41.8UT 7:35:41.8

6868

UT 7:35:42.0UT 7:35:42.0

6969

UT 7:35:42.5UT 7:35:42.5

7070

UT 7:35:42.9UT 7:35:42.9

7171

UT 7:35:44.1UT 7:35:44.1

7272

UT 7:35:46.4UT 7:35:46.4

7373

UT 7:35:46.9UT 7:35:46.9

7474

The rest is history….The rest is history….

It took us a while to dig out these eventsIt took us a while to dig out these eventsfrom the raw data tape, but once we didfrom the raw data tape, but once we didthe signal was dramatic.the signal was dramatic.The normal rate of similar events isThe normal rate of similar events is one every 5 days.one every 5 days.From random probability, 8 such events in From random probability, 8 such events in

6 sec will occur:6 sec will occur:

Once every 2X10Once every 2X1034 34 years ! years !

7575

What a crazy coincidence…What a crazy coincidence…

That’s just a little greater thanThat’s just a little greater than

the lifetime limits on the proton!the lifetime limits on the proton!

G: It’s not a coincidence… Gabi, have you been playing with the numbers again?

g: I cannot tell a lie Boss…

I installed a string theory with proton lifetime = 2.137 X 1034 years

7676

The CastThe Cast

7777

The Diaspora, 1987The Diaspora, 1987

7878

The DataThe Data

Phys Rev D37 3361 (1988)

7979

We’ll hear a lot moreWe’ll hear a lot more

in the next three days about the nice thingsin the next three days about the nice things

we have learned from the SN1987a data. we have learned from the SN1987a data.

We sure would like to see another one!We sure would like to see another one!

There’s a lot more to be learned,There’s a lot more to be learned,

Including clearing up some mysteries like… Including clearing up some mysteries like…

Hint, hint

8080

The Angle-energy DistributionThe Angle-energy Distribution

8181

Hopefully, that will be accomplished by some of you intelligent designers in the

audience!

8282

Whoops!... More of the Cast:Whoops!... More of the Cast:

g

G:

8383

g: “Boss, There’s a lot of physicists down there

that still don’t believe in Intelligent Design. Maybe they need

another Big Lucky Break to convince them.”

G: “Send ‘em to G: “Send ‘em to Hawaii !”Hawaii !”