Transcript Hubble Science Briefing CLASH Cluster Lensing And Supernova survey with Hubble Hubble Uses Gravitational Lensing to Discover Most Distant Galaxies Dan Coe Space Telescope Science Institute Jan.

Hubble Science Briefing
CLASH
Cluster Lensing And Supernova survey with Hubble
Hubble Uses Gravitational Lensing
to Discover Most Distant Galaxies
Dan Coe
Space Telescope Science Institute
Jan 24, 2013
Dan Coe - STScI
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Hubble is now observing galaxies
97% of the way back to the Big Bang,
during the first 500 million years
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Previous searches for galaxies in the first 500 Myr came up short.
Only one candidate was found where six were expected.
This suggested a dramatic buildup in galaxy numbers.
time
TODAY (13.7)
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Dan Coe - STScI
BIG BANG
adapted from Bouwens12
see also Oesch12
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Previous searches for galaxies in the first 500 Myr came up short.
Only one candidate was found where six were expected.
This suggested a dramatic buildup in galaxy numbers.
(billions
.of years)
time
BIG BANG
(log suns / year / cubic megaparsec)
TODAY (13.7)
Jan 24, 2013
Dan Coe - STScI
adapted from Bouwens12
see also Oesch12
4
Such dramatic evolution could have
surprising implications
• Did galaxies only just start forming then?
(Unlikely based on stellar masses observed later)
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Such dramatic evolution could have
surprising implications
• Not enough faint galaxies to reionize the universe
(stripping electrons - from atoms)?
May require a more exotic energy source such as dark matter self-annihilation
Reionization
+
-
+
+
Robertson10
Atoms, they
come together
time
Atoms, they
fall apart
We are all
made of stars
– paraphrasing song lyrics by Moby
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Two complementary programs
have now identified five candidate galaxies
in the first 500 million years
• UDF
Ultra Deep Field (now even deeper!)
• “CLASH” – using gravitational lensing from
“cosmic telescopes” to magnify the distant
universe
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The Hubble Space Telescope,
now in its 23rd year of operation,
is more powerful and advanced than ever
Servicing Mission 4 (2009)
The Wide Field
Camera 3 (WFC3)
was installed during
Servicing Mission 4
(center white panel)
Improved imaging
at near-ultraviolet
and near-infrared
wavelengths
May 2009
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Hubble now has four operational
imagers / spectrographs
• Two primary cameras:
– Advanced Camera for Surveys (ACS)
– Wide Field Camera 3 (WFC3)
• Two spectrographs:
– Space Telescope Imaging
Spectrograph (STIS)
– Cosmic Origins Spectrograph (COS)
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J. Hecht
LaserFocusWorld
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Hubble Multi-Cycle Treasury Program
• To help realize Hubble’s full potential
• First ever call for multi-year proposals
• 39 programs were proposed, 3 were approved
– Combined 5 months of Hubble observing time,
carried out over 3 years: Fall 2010 – Fall 2013
– PHAT: stars
– CANDELS: galaxies
– CLASH: galaxy clusters
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PHAT
Panchromatic Hubble Andromeda Treasury Survey
PI: Julianne Dalcanton
region being observed with Hubble
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PHAT
Panchromatic Hubble Andromeda Treasury Survey
PI: Julianne Dalcanton
PHAT progress as of Nov 2012;
Hubble will image 414 contiguous fields
upon completion
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CANDELS
Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey
PIs: Sandra Faber & Harry Ferguson
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CLASH
Cluster Lensing And Supernova survey with Hubble
PI: Marc Postman
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CLASH
Cluster Lensing And Supernova survey with Hubble
PI: Marc Postman
Observing 25 galaxy clusters including MACS0416-24 (background)
Two primary goals of CLASH are to use
gravitational lensing to:
– Reveal dark matter, the “scaffolding”
of structure formation
– Magnify galaxies in the distant universe
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Gravitational lensing in action
Animation: http://www.spacetelescope.org/videos/heic1106a/ – NASA, ESA & L. Calçada
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Gravitational lensing in action
Cluster mass bends space
according to Einstein’s
Relativity
Light follows the
curved space to us
like golf balls along
a putting green
Animation: http://www.spacetelescope.org/videos/heic1106a/ – NASA, ESA & L. Calçada
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Strong gravitational lensing produces
multiple magnified images of distant galaxies
distant galaxy
observed when
the universe
was 900 million
years old
Abell 383 – NASA, ESA, J. Richard, J. P. Kneib; M. Postman
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Gravitational
Lensing
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Wine
Glass
Lensing
Phil Marshall
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Most of the mass is dark matter
Abell 1689 – D. Coe
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Most of the mass is dark matter
as revealed by gravitational lensing
Abell 1689 – D. Coe
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Dark matter makes up most of the stuff in the universe
Everything
Dark
Energy
72%
Matter
Dark
Matter
23%
Dark
Matter
82%
Gas
15%
Stars 2%
Heavy
Elements 0.1%
Neutrinos 1%
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Dark Matter FAQ (Frequently Asked Questions)
Is that like black holes?
Black holes make up some of the dark matter,
but not much
Is Pluto a planet?
Sorry, not anymore.
Yes, we are redoing all the horoscopes.
Dark matter may be made of particles
we’ve yet to discover
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Dark Matter FAQ (Frequently Asked Questions)
Is that like black holes?
Black holes make up some of the dark matter,
but not much
Is Pluto a planet?
Sorry, not anymore.
And yes, we are redoing all the horoscopes.*
Dark matter may simply be made of particles
we’ve yet to discover (the “next Higgs”)
*We don’t actually do the horoscopes
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MACS 1206-08
Zolt Levay
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A river runs through it
MACS 1206-08
Zolt Levay
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A river runs through it
MACS 1206-08
Zolt Levay
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MACS 0647+70
Zolt Levay
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Multiple images of
strongly lensed
galaxies
Adi Zitrin
MACS 0647+70
Zolt Levay
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Three strongly lensed images of MACS0647-JD:
a candidate for the most distant galaxy yet known
may have
highest
“redshift”
yet observed
z ≈ 11
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Galaxy redshifts are distant galaxy
Earth
primarily due to
expansion of space,
Emitted blue light…
not Doppler shift
time
Expanding universe
stretches light
to longer wavelengths
…stretched to green…
Redshift (z) =
stretch factor
minus one
…then red (or even infrared) when observed
ESO animation:
Jan 24, 2013
http://www.eso.org/public/videos/redshiftv/
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Observed Lyman break reveals redshift
of a distant galaxy
Ultraviolet light with
wavelengths lower than
Lyman-alpha (0.1216 μm)
never reaches us
+
redshifted galaxy light
These energetic photons
get absorbed as they
ionize / excite atoms
redshifted Lyman break
Observed
Flux
Lyman-alpha forest /
Gunn-Peterson trough
0.1216(1+z) μm
Wavelength
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MACS0647-JD appears to be at redshift 11,
its light traveling 13.3 billion years to reach us.
During that time, the universe has expanded in size by a factor of 12,
redshifting the Lyman break from 0.1216μm to 1.46μm.
unprecedented number of
J-band
Hubble filters
Ultraviolet light
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Visible light
Infrared light
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MACS0647-JD only appears
in the two reddest Hubble filters
JD = “J-band dropout”
Visible light
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J-band
6σ
12σ
7σ
15σ
6σ
10σ
Infrared light
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MACS0647-JD is not visible in
Spitzer images at longer wavelengths
Hubble
Spitzer
This is good.
Bright detections
would have suggested a
red less-distant galaxy
as opposed to a
blue more-distant galaxy.
The current Spitzer images
are relatively shallow.
By observing deeper,
we can hope to detect
MACS0647-JD and
measure its age and dust
content (pollution level).
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Starburst
Redshifted
or just red
(old / dusty)?
Spiral
Age
Galaxies do come
in different colors,
but the observed
colors of
MACS0647-JD
can only be
explained by a very
distant galaxy
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Elliptical
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Another candidate
in the first 500 Myr
MACS1149-JD
z ≈ 9.6 (490 Myr)
Wei Zheng et al.
Nature 489, 406
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Ultra Deep Field 2012
• 2004 – ACS (optical) + NICMOS (infrared)
• 2009 – WFC3/IR (better infrared)
– released in 2012 as “ eXtreme Deep Field ”
• 2012 – WFC3/IR over twice as deep
R. Ellis
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Ultra Deep
Field 2012
7 candidates for
galaxies observed in
first 570 million years,
including a new
candidate for most
distant galaxy known
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Another candidate for most distant galaxy known
added in 2012:
R. Ellis
UDF12-3954-6284
z = 11.9+0.3-0.5
(370 Myr after big bang)
F105W
F140W
F160W
only detected in the reddest Hubble filter
Originally identified in 2011 by R. Bouwens
who estimated z = 10.3 ± 0.8 (450 Myr)
Revised to z ≈ 11.9 by R. Ellis
based on F140W non-detection,
though they caution it may be a less distant
extreme emission line galaxy
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So what is the most distant galaxy yet known?
“Mr. Hubble says that trophies are for
people with self-esteem issues.”
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Most distant galaxy candidates discovered to date
Redshift
(68% CL)
age of
universe
object
F160W AB
magnitude
Flux (nJy)
reference
field /
survey
11.9 +0.3-0.5
370 Myr
UDF12-3954-6284
29.3 ± 0.2
7
Ellis13,
Bouwens11
UDF12
10.8 ± 0.3
420 Myr
MACS0647-JD
25.9, 26.1, 27.3
Coe13
CLASH
9.6 ± 0.2
490 Myr
MACS1149-JD
25.7 ± 0.07
194
Zheng12
CLASH
9.5 +0.4-0.8
500 Myr
UDF12-4106-7304
29.7 ± 0.3
5
Ellis13
UDF12
9.5 +0.4-0.7
500 Myr
UDF12-4265-7049
29.7 ± 0.4
5
Ellis13
UDF12
9.2 +0.4-0.6
520 Myr
MACS1115-JD
26.2 ± 0.2
115
Bouwens13
CLASH
9.0 +0.3-0.8
540 Myr
MACS1720-JD
26.9 ± 0.3
66
Bouwens13
CLASH
162 - 42
Highest redshifts spectroscopically confirmed
Redshift
age of
universe
object
AB magnitude
reference
7.215 (spec-z)
720 Myr
SXDF-NB1006-2
24.6 narrow band
Shibuya12
7.213 (spec-z)
720 Myr
GN-108036
25.5 Y (1μm)
Ono12
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UDF + CLASH provide our first views of first 500 million years,
but more observations are required to constrain cosmic evolution
1.5Gyr 1Gyr 800
600 500
400 Myr after big bang
Cosmic star
formation rate
density
Ellis et al.
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Lensing is more efficient at
discovering the most distant galaxies
Log galaxies
per
Hubble image
Time required with Hubble
Bright
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Faint
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To lens or not to lens?
“Blank” Field
Lensed
Unobstructed view:
luminosities
more certain
Magnified:
more efficient,
detailed study
We can map out the
lensing dark matter
well but not perfectly
Simone Kay
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We have decided to do both!
Hubble will observe lensed and “blank” fields simultaneously in parallel.
WFC3/IR
ACS
“blank” field
cluster core
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Swap cameras 6 months later / earlier
ACS
WFC3/IR
“blank” field
cluster core
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The Frontier Fields: first 4 of 6 selected
MACS0717+37
Abell 370
Hubble will obtain the first
ever deep lensed IR images,
while simultaneously
observing more “blank”
deep fields in parallel
MACS0416-24
Pandora’s Cluster
Abell 2744
dark matter
gas
nearly 2 months
on Hubble
over 3 years:
Fall 2013 –
Fall 2016
observations of
final 2 cluster-field
pairs subject to
approval
http://www.stsci.edu/hst/campaigns/frontier-fields/
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The Frontier Fields will help address questions
about the early universe
• Do we find the numbers of galaxies we expect,
or do we observe more dramatic evolution?
• Were there enough galaxies to reionize the
early universe?
• Can we detect any pristine galaxies yet to be
enriched by supernova explosions?
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Hubble cannot observe the first 300 million years.
The James Webb Space Telescope is required
to observe and study the first galaxies.
Hubble’s
limit:300 million
years
= redshift 13
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CLASH and the UDF are performing frontier science,
discovering galaxy candidates in the first 500 Myr
with Hubble and Spitzer
• The Hubble Frontier Fields will build upon
these efforts, improving the galaxy census
300 – 500 Myr after the big bang
• The James Webb Space Telescope is required
to observe the first galaxies at earlier times
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Thank you
Jan 24, 2013
Dan Coe - STScI