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 Last Version: DR3.5  Released June 2012  Pipeline:  Optimised De- glitcher  BriGAdE  Allow Dark Pixel drift removal.

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Presentation on theme: " Last Version: DR3.5  Released June 2012  Pipeline:  Optimised De- glitcher  BriGAdE  Allow Dark Pixel drift removal."— Presentation transcript:

1 Matthew.Smith@astro.cf.ac.uk

2  Last Version: DR3.5  Released June 2012  Pipeline:  Optimised De- glitcher  BriGAdE  Allow Dark Pixel drift removal  Manual Jump and glitch-tail removal  New Pixel sizes: 6, 8, 12 "

3 V1 V2 V3 V4  Latest Version: DR4  Released June 2012  Updates from DR3.5 to DR4:  PMW cal factor v5 to v8 applied to map (1.0067)  Second-order deglitching  Relative Gain Corrections for extended emission

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5  For extra-galactic science we have optimum SPIRE pipeline (cirrus scale structures may- not be optimal)  Pointing Products  Star-Tracker Temperatures were changed on OD 320 to prevent hot-pixel issues  Herschel updated on OD 761 to account for changes  New pointing products OD 320-761 available (~ 2")

6  Planned Updates on DR4  NEW CALIBRATION! (point + ext)  New Pointing Product  Updates not going to be applied  Planck Zero Level Calibration  De-striper (except on a set of cirrus maps for Simone

7  New Neptune measurements by George  Increase of ∼3%, ∼2% & ∼1% at 250, 350 and 500µm  Aperture Efficiency values now included (fairly small)  Long term – will be new updates on the assumed Neptune and Uranus models

8  Chris North, Matt Griffin, & co  Applies to fully extended until >100'  Working on adaptive script for intermediate sources 10 – 100'. Will require TWO versions of SPIRE for point/extended or even individual object maps that are optimised to their size

9  Old Philosophy – FUDGE IT:  Modify the filter curve with a λ 2 weighting  Wrong for 2 reasons:  1: Beam solid angle varies as λ 1.7  2: Not a single value of beam area appropriate for sources  Depending on your source spectral index could correct the wrong way.

10  Why the difference?  See white board!  New Philosophy  As well as apply colour–corrections account for varying beam area across band  Talking somewhere in the region 0-10% change in values  New pipeline surface brightness product in MJy/sr  Is a Planck zero level corrected map as well (but not really worth it)

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13  An original aim of the HRS (and many other surveys) to find cold dust in outskirts of galaxies.  Dust could be driven out or formed outside disk.  Has been detected by quasar absorption (Menard et al. 2010) – see next slide.  Not been possible to detect emission before as dust is cold and very low surface brightness.  Still work in progress...

14  Potential Questions?  How far can we detect dust emission  What are the properties of the dust at these wavelengths  Extreme environment for SF etc…  Only used SPIRE only due to sensitivity / reduction method / areas covered  Still work in progress

15  uses SDSS  ∼85,000 quasars at z > 1  Correlated with 24 million galaxies at z∼0.3  Find reddening and magnification  Half of dust is outside galaxies

16 HRS object Criteria: Late-type galaxies Indentified as detection Extended Source No other bright contaminating object No heavy cirrus contamination Inclination < 60°

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18  Restricted to galaxies with D25 > 3ˊ

19  Have randomly chosen 32 galaxies (1/4 sample) and repeated procedure  Measured where it crosses a fixed threshold (equivalent to 1.8R 25 )  Repeated 40,000 times  Results do not vary by a large amount (±0.15 R 25 )

20  Probably Not!  Nearby Objects  Large extended objects  Bright  Maps not large enough  Wide Field Surveys, e.g., H-ATLAS  Many objects so can be sensitive  Large areas so can reach high scales  Angular size is smaller, flux of central beam dominates at radii < 2.0R 25

21  Minimise χ 2 model by:  Trial Model  Convolving it with beam  Calculate χ 2  Following Schruba et al. 2011 do not fit centre 30˝  Need 2 exponentials

22  The fraction of dust emission between 1-2 R 25 is 6.6, 8.0 and 10.6% for the 250, 350 and 500µm band.  If integrate the broken-exponential model from 0⇢∞ find that 4.2% of emission at 250µm  Rough agreement with 15kpc Medard value but I need to redo this.

23  Work in Progress…  All images smoothed and re-gridded to PLW images  Temperature stabilises around 16K  Means a higher fraction of dust mass outside R25 than fraction 250µm emission

24  Difference is less prounonced as Cortese 2010  Individual objects are in agreement  Highly HI def are significantly different from HI def < 0.0 (Mann-Whitney U statistic)

25  Not yet Investigated…

26 Are low mass galaxies cosmic hoovers picking up dust expelled from high stellar mass galaxies?

27  Schruba et al. with CO with HERACLES reach 1.0-1.2R25  HI Paolo Serra suggested a thesis by Thomas Martinsson  Unknown for other wavelengths (e.g., UV)?

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