Hubble Science Briefing - HubbleSOURCE:...

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


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.


adapted from Bouwens12 see also Oesch12

BIG BANG time TODAY (13.7)


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)


Such dramatic evolution could have surprising implications

• Not enough faint galaxies to reionize the universe (stripping electrons from atoms)?


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


The Hubble Space Telescope, now in its 23rd year of operation,

is more powerful and advanced than ever

Servicing Mission 4 (2009)


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)


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



PHAT Panchromatic Hubble Andromeda Treasury Survey

PI: Julianne Dalcanton

region being observed with Hubble


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



PI: Marc Postman



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


Observing 25 galaxy clusters including MACS0416-24 (background)

Gravitational lensing in action


Animation: http://www.spacetelescope.org/videos/heic1106a/ – NASA, ESA & L. Calçada

Gravitational lensing in action


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


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


Gravitational Lensing


Wine Glass Lensing

Phil Marshall


Abell 1689 – D. Coe

Most of the mass is dark matter


Most of the mass is dark matter as revealed by gravitational lensing

Abell 1689 – D. Coe


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


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


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


Zolt Levay MACS 1206-08



A river runs through it



A river runs through it


Zolt Levay

MACS 0647+70


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


may have highest “redshift” yet observed z ≈ 11


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


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.


Visible light Infrared light Ultraviolet light

Hubble filters J-band unprecedented number of


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


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


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


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


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



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?


“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


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


Ellis et al.

Cosmic star formation rate density

500 400 800 600 1Gyr Myr after big bang 1.5Gyr


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?


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


ACS

Swap cameras 6 months later / earlier

WFC3/IR

“blank” field

cluster core



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?


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

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


Thank you

Jan 24, 2013 Dan Coe - STScI

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