hubble science briefing - hubblesource:...
TRANSCRIPT
Jan 24, 2013 Dan Coe - STScI 1
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
Hubble is now observing galaxies 97% of the way back to the Big Bang,
during the first 500 million years
Jan 24, 2013 Dan Coe - STScI 2
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.
Jan 24, 2013 Dan Coe - STScI 3
adapted from Bouwens12 see also Oesch12
BIG BANG time TODAY (13.7)
Jan 24, 2013 Dan Coe - STScI 4
adapted from Bouwens12 see also Oesch12
TODAY (13.7) BIG BANG time
(lo
g su
ns
/ ye
ar /
cu
bic
meg
apar
sec)
(billions .of years)
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.
Such dramatic evolution could have surprising implications
• Did galaxies only just start forming then?
(Unlikely based on stellar masses observed later)
Jan 24, 2013 Dan Coe - STScI 5
Such dramatic evolution could have surprising implications
• Not enough faint galaxies to reionize the universe (stripping electrons from atoms)?
Jan 24, 2013 Dan Coe - STScI 6
Robertson10
time
May require a more exotic energy source such as dark matter self-annihilation
+
-
+
-
+
-
Atoms, they come together
Atoms, they fall apart
We are all made of stars
– paraphrasing song lyrics by Moby
Reionization
-
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
Jan 24, 2013 Dan Coe - STScI 7
The Hubble Space Telescope, now in its 23rd year of operation,
is more powerful and advanced than ever
Servicing Mission 4 (2009)
Jan 24, 2013 Dan Coe - STScI 8
May 2009
Improved imaging at near-ultraviolet and near-infrared wavelengths
The Wide Field Camera 3 (WFC3) was installed during Servicing Mission 4 (center white panel)
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)
Jan 24, 2013 Dan Coe - STScI 9
J. Hecht LaserFocusWorld
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
Jan 24, 2013 Dan Coe - STScI 10
Jan 24, 2013 Dan Coe - STScI 11
PHAT Panchromatic Hubble Andromeda Treasury Survey
PI: Julianne Dalcanton
region being observed with Hubble
Jan 24, 2013 Dan Coe - STScI 12
PHAT Panchromatic Hubble Andromeda Treasury Survey
PI: Julianne Dalcanton
PHAT progress as of Nov 2012; Hubble will image 414 contiguous fields upon completion
CANDELS Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey
PIs: Sandra Faber & Harry Ferguson
Jan 24, 2013 Dan Coe - STScI 13
CLASH Cluster Lensing And Supernova survey with Hubble
PI: Marc Postman
Jan 24, 2013 Dan Coe - STScI 14
CLASH Cluster Lensing And Supernova survey with Hubble
PI: Marc Postman
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
Jan 24, 2013 Dan Coe - STScI 15
Observing 25 galaxy clusters including MACS0416-24 (background)
Gravitational lensing in action
Jan 24, 2013 Dan Coe - STScI 16
Animation: http://www.spacetelescope.org/videos/heic1106a/ – NASA, ESA & L. Calçada
Gravitational lensing in action
Jan 24, 2013 Dan Coe - STScI 17
Animation: http://www.spacetelescope.org/videos/heic1106a/ – NASA, ESA & L. Calçada
Light follows the curved space to us like golf balls along
a putting green
Cluster mass bends space according to Einstein’s
Relativity
Jan 24, 2013 Dan Coe - STScI 18
Strong gravitational lensing produces multiple magnified images of distant galaxies
Abell 383 – NASA, ESA, J. Richard, J. P. Kneib; M. Postman
distant galaxy observed when the universe was 900 million years old
Jan 24, 2013 Dan Coe - STScI 19
Gravitational Lensing
Jan 24, 2013 Dan Coe - STScI 20
Wine Glass Lensing
Phil Marshall
Jan 24, 2013 Dan Coe - STScI 21
Abell 1689 – D. Coe
Most of the mass is dark matter
Jan 24, 2013 Dan Coe - STScI 22
Most of the mass is dark matter as revealed by gravitational lensing
Abell 1689 – D. Coe
Jan 24, 2013 Dan Coe - STScI 23
Dark Matter
23%
Dark Energy
72%
Stars 2%
Neutrinos 1%
Heavy Elements 0.1%
Gas 15%
Dark Matter
82%
Matter Everything
Dark matter makes up most of the stuff in the universe
Jan 24, 2013 Dan Coe - STScI 24
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
Jan 24, 2013 Dan Coe - STScI 25
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
Jan 24, 2013 Dan Coe - STScI 26
Zolt Levay MACS 1206-08
Jan 24, 2013 Dan Coe - STScI 27
Zolt Levay MACS 1206-08
A river runs through it
Jan 24, 2013 Dan Coe - STScI 28
Zolt Levay MACS 1206-08
A river runs through it
Jan 24, 2013 Dan Coe - STScI 29
Zolt Levay
MACS 0647+70
Jan 24, 2013 Dan Coe - STScI 30
Zolt Levay
MACS 0647+70
Multiple images of strongly lensed
galaxies Adi Zitrin
Three strongly lensed images of MACS0647-JD: a candidate for the most distant galaxy yet known
Jan 24, 2013 Dan Coe - STScI 31
may have highest “redshift” yet observed z ≈ 11
Jan 24, 2013 Dan Coe - STScI 32
Galaxy redshifts are primarily due to expansion of space, not Doppler shift
Earth distant galaxy
Emitted blue light…
Expanding universe stretches light to longer wavelengths
…stretched to green…
…then red (or even infrared) when observed ESO animation: http://www.eso.org/public/videos/redshiftv/
Redshift (z) = stretch factor minus one
time
Wavelength
Observed Lyman break reveals redshift of a distant galaxy
Jan 24, 2013 Dan Coe - STScI 33
Observed Flux
0.1216(1+z) μm
+
-
redshifted Lyman break
These energetic photons get absorbed as they ionize / excite atoms
redshifted galaxy light
Ultraviolet light with wavelengths lower than
Lyman-alpha (0.1216 μm) never reaches us
Lyman-alpha forest / Gunn-Peterson trough
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.
Jan 24, 2013 Dan Coe - STScI 34
Visible light Infrared light Ultraviolet light
Hubble filters J-band unprecedented number of
Jan 24, 2013 Dan Coe - STScI 35
6σ
7σ
6σ 10σ
15σ
12σ
J-band
MACS0647-JD only appears in the two reddest Hubble filters
JD = “J-band dropout”
Visible light Infrared light
Jan 24, 2013 Dan Coe - STScI 36
MACS0647-JD is not visible in Spitzer images at longer wavelengths
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).
Hubble Spitzer
Jan 24, 2013 Dan Coe - STScI 37
Redshifted or just red
(old / dusty)?
Starburst
Elliptical
Spiral
Age Galaxies do come in different colors, but the observed
colors of MACS0647-JD
can only be explained by a very
distant galaxy
MACS1149-JD
z ≈ 9.6 (490 Myr) Wei Zheng et al. Nature 489, 406
Jan 24, 2013 Dan Coe - STScI 38
Another candidate in the first 500 Myr
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
Jan 24, 2013 Dan Coe - STScI 39
R. Ellis
Ultra Deep Field 2012
7 candidates for galaxies observed in
first 570 million years, including a new
candidate for most distant galaxy known
Jan 24, 2013 Dan Coe - STScI 40
Jan 24, 2013 Dan Coe - STScI 41
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
Another candidate for most distant galaxy known
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)
R. Ellis added in 2012:
So what is the most distant galaxy yet known?
Jan 24, 2013 Dan Coe - STScI 42
“Mr. Hubble says that trophies are for people with self-esteem issues.”
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, 27.3 162 - 42 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
Jan 24, 2013 Dan Coe - STScI 43
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
Highest redshifts spectroscopically confirmed
UDF + CLASH provide our first views of first 500 million years, but more observations are required to constrain cosmic evolution
Jan 24, 2013 Dan Coe - STScI 44
Ellis et al.
Cosmic star formation rate density
500 400 800 600 1Gyr Myr after big bang 1.5Gyr
Jan 24, 2013 Dan Coe - STScI 45
Lensing is more efficient at discovering the most distant galaxies
Bright Faint
Time required with Hubble
Log galaxies per
Hubble image
Simone Kay
“Blank” Field Lensed
To lens or not to lens?
Jan 24, 2013 Dan Coe - STScI 46
Magnified: more efficient, detailed study
Unobstructed view: luminosities more certain
We can map out the lensing dark matter
well but not perfectly
ACS
We have decided to do both! Hubble will observe lensed and “blank” fields simultaneously in parallel.
WFC3/IR
cluster core
“blank” field
Jan 24, 2013 Dan Coe - STScI 47
ACS
Swap cameras 6 months later / earlier
WFC3/IR
“blank” field
cluster core
Jan 24, 2013 Dan Coe - STScI 48
Jan 24, 2013 Dan Coe - STScI 49
The Frontier Fields: first 4 of 6 selected
MACS0717+37
Pandora’s Cluster Abell 2744
Abell 370
MACS0416-24
http://www.stsci.edu/hst/campaigns/frontier-fields/
Hubble will obtain the first ever deep lensed IR images, while simultaneously observing more “blank” deep fields in parallel
nearly 2 months on Hubble over 3 years: Fall 2013 – Fall 2016 observations of final 2 cluster-field pairs subject to approval
dark matter gas
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?
Jan 24, 2013 Dan Coe - STScI 50
Hubble cannot observe the first 300 million years. The James Webb Space Telescope is required
to observe and study the first galaxies.
Jan 24, 2013 Dan Coe - STScI 51
Hubble’s limit:300 million
years = redshift 13
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
Jan 24, 2013 Dan Coe - STScI 52
Thank you
Jan 24, 2013 Dan Coe - STScI