HerMES (Herschel Multi-tiered Extragalactic...
Transcript of HerMES (Herschel Multi-tiered Extragalactic...
HerMES
Photometric wedding cake survey using SPIRE instrument on Herschel SPIRE (Spectral and Photometric Imaging Receiver)
250, 350, and 500 μm
Is closely coordinated with PEP (PACS Evolutionary Probe Survey) PACS
75, 100, and 170 μm
Fields chosen to make use of available ancillary data from x-ray to radio
HerMES
Wedding cake survey 6 tiers
Zooming in from larger fields to smaller fields while increasing sensitivity
Why would we want to do this?
Galaxies can be very bright in sub-mm regime
Especially if they are star forming/bursting
Especially if they are redshifted such that their SED peak shifts into the specified windows
Why would we want to do this?
In terms of gauging total bolometric luminosity, dust masses, and star formation rates, HerMES (and Herschel) are
ideally suited,
especially so for
sources at
redshifts ~2-3.
http://www.eso.org/~rsiebenm/sb_models/
Why would we want to do this?
Madau plot
http://www.macalester.edu/astronomy/courses/physics50/spring2002.html
Why would we want to do this?
How is HerMES going to solve all of astronomy? Resolve infrared background
Constrain bolometric luminosities Constrain star formation history
Reveal structure of early universe galaxies (IE cold dust components, etc)
Field Choice
Well known fields (GOODS-N / HDFN, Lockman) Ancillary data crucial to the science Find luminosities Estimate presence of dust components Estimate star formation rates Combat confusion…
http://herschel.esac.esa.int/SDP_wkshops/presentations/IR/5_Oliver_HerMES_SDP2009.pdf
A Bit More on Confused Fields
We can find a statistical estimate of sources and brightnesses without extracting any individual sources by looking at the variations in pixel brightness
“P(D) analysis”
See: Observations of HDF with ISO – III Source counts and P(D) analysis, S. Oliver et al, MNRAS 1997
BLAST: Resolving the Cosmic Sub-mm Background, G. Marsden, et al, eprint arXiv: 0904.1205 (2009).
Current Status
SD phase observations complete
May 4-7 ESLAB Symposium
July 15 A&A issue Early Data Release
Nov 2010 Data Release 1
Nov 2012 Data Release 2
The End / Resources
http://herschel.esac.esa.int/SDP_wkshops/presentations/IR/5_Oliver_HerMES_SDP2009.pdf
http://herschel.esac.esa.int/
http://astronomy.sussex.ac.uk/~sjo/Hermes/
What is Herschel?
Infrared/sub-mm satellite
Launched on May 14
Orbits in Lissajous around L2
3.5 m primary
What is Herschel? 3 Instruments
HIFI
High-res heterodyne spectrometer
157-625 μm
PACS
Imaging photometer and integral field line spectrometer
Spectrometer: 55-105 and 105-210 um
(60-85 OR 85-130) AND 130-210 μm
SPIRE
Spectrometer and photometer
Photometer: 250, 350, 500 um
Spectrometer: 194-672 μm
60-672 um (Far-IR to Sub-mm) Cooler objects, 5-50 K
Bright atomic and molecular emission lines from gas 10-few hundred K
Good at seeing dust-enshrouded sources
Good gauge of SFR