Supernova Remnants and WFC3

Transcription

1 Supernova Remnants and WFC3 Justin Spengel Using our new filters to spot another Sol?

2 Our new Tech WFC3 installed May 14th, 2009 Pair of 8MP UV/visible CCDs Single 1024x1024 IR CCD Picture public domain from NASA Between them, we can more effectively isolate frequencies between nm.

3 What to do with it? Shiny new wallpapers Replace or augment old images Penetrate new regions of space with our newfound clarity and precision. Photo in Public Domain

4 Supernova Remnants Dopita, Blair, and many others, including our own Windhorst brought the focus around to M83, to discern, classify, and analyze potential Supernova remnants. 60 candidates using several filters. Ha, [S II ], Hb, [O III ] and [O II ] Two populations Nuclear & Spiral Arm Inter-Arm WFC3 HST

5 Why do we care? The presence of live 60-Fe in our early system tells us that we formed near a massive star, and that Supernova activity plays a critical role in system development! WFC3 HST

6 Meteorites: Cosmic Lumbar Puncture Meteorites give us a snapshot of the protoplanetary disc. -Chemical -Physical -Thermodynamic -Time constraints; Short Lived Radionuclides Like clocks- measure decay, find age. 26 Al, 60 Fe, 36Cl, 41Ca, 53Mn, etc. 60 Fe in our early system can only fit into our models if the sun were near a massive neighbor that went supernova.

7 Small Star Formation We mainly studied star creation in regions like the Taurus Auriga molecular cloud. Since it is so close, we can analyze otherwise unobservable phenomena But the isolation is not necessarily typical of low mass star formation. WFC3 will enable us to analyze other more appropriate regions- like M83 Taurua Auriga complex. Photo courtesy of Cotswold Observatory

8 Taurus Auriga is a particularly odd specimen More Binary Stars than would be expected Fewer Brown Dwarfs The initial mass function peaks at a higher mass (~0.8M than is expected. Deficient for masses >1M Sun ) Sun 70-90% of young stars within 2 kpc formed in rich embedded clusters. (Lada & Lada; 2003) ~75% are in clusters with live massives (>8M) Others likely contained massives previously!

9 We know this? SLRs again 26 Al was present in our young Solar System From nearby Supernova Or by spallation involving Solar cosmic rays Self-contained (no outside source for radioisotopes) Accounts for live 10 Be (only from spallation) In 2003,Tachibana & Huss reported live 60 Fe in our early system. 60 Fe does NOT form in spallation Only in supernovae! Other spallation-unfriendlies include 182 Hf & 107 Pd

10 How the supernova effects the H II region. Excerpt from Hester & Desch (2005)

11 NOT Supernova Triggered Formation Triggered infers the direct creation of the formation by the sudden burst of energy of the supernova explosion. The process discussed here affects the environment in which the stars are produced The supernova is not the dominant energy source Even during the supernova event, the energy will likely not dominate other effects. More difficult to spot, track, and decipher, even with WFC3.

12 So how do we spot them? Techniques developed in Mathewson, Healey, Clark, and Westerlund ( ) Non-thermal Spectra Caused by shockwaves through interstallar medium More reliant on ISM Regions excited by radiative shocks + non-thermal radio or X-ray from the heated gas behind the wave confirm SNR Tycho's Supernova

13 M83 (NGC5236) SAB(s)c Nucleus dominated by massive OB stars 6 optically detected Supernovae in the last century Spiral arm Inclination 24 degrees Angular size 13 minutes 4.56Mpc (NED) Nucleus and spiral arms exhibit star formation (not necessarily visible) 71 SNR candidates (Blair & Long 2004)

14 Methods Paper used [SII]/Ha ratio and relative [OII] emission Data from WFC3 via WFC SOC ERS Science Oversight Committee Early Release Science Program. Field was chosen to cover inner spiral arm and nucleus 3-4 dithered exposures per narrowband filter. Outer field planned but not yet acquired Combined through MultiDrizzle (Fruchter & Hook 2009) All SNR candidates spatially resolved WFC3 resolution ( arcsec) equates to 0.9pc Spatial resolution (0.06 arcsec) equates to 1.7pc

15 Weighted pairs of wideband images combined for reference with narrowband F336W and F438W for [OII] F438W and F555W for Hb and [OIII] F555W F814W for Ha and[sii]

16 Working with the data Weights derived from the log variance between that band and the emission line Scaled images subtracted from the line image to produce 'pure' mapping Color variance between older reds in nucleus and and hot blues in arms Reconciled only partway. M83 core emission line

17 Disk SNR Outside 300pc radius circle around center cluster Relaxed definition of SNR F673N/F657N > 0.3 instead of [SII]/Ha >0.4 Clusters are easily screened Centrally concentrated HST F657N filter transmits [NII] line As strong as ~50% Ha SNRs appear as shells Faint in [OII] filter Chandra image of M83

18 40 SNR candidates The coordinates agree with the 12 in common with Blair & Long (2004) Scaled in order of increasing RA M83-SNR-1-14 structure appears as double-lobe radio source Like W50 Potential binary black hole! Also M83-SNR-1-12

19 Nuclear SNR Holy Toledo Batman, this is harder! Interstellar emissions with high [SII]/Ha ratio Reddening + older star population disrupts color subtraction for [SII] Strong Ha emissions in the region, masking contrast with SNR shells Requires new technique High [OIII] implies chemical abundance Means low temperatures (<5000K) Means supressed [OII]

20 So now what? Shock-excited [OII] is hotter (~12000K) Stronger emissions Unfortunately, the line is heavily attenuated No better than 50% completeness (this side of the midplane) m83

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22 O-strong nebulae Usually very low [OIII] emissions Any object with high [OIII] is interesting Wolf-Ring nebulae Supernova candidates Reverse shock (young SNRs) Radiative phase (normal) courtesy of uocmas.info pic of the day

23 M83-SRC-1-01 Small arc, diffused Ha M83-SRC-1-02 Very faint extend [OIII] M83-SRC-1-03 Cluster of O-knots within [SII] + Ha shell Possible analogue of N132D (large magellanic cloud) M83-SRC-1-04 Strong [OII] + [OIII] Ha + weak [SII] M83-SRC-1-05 Full [OII] ring Half shell of Ha within

24 SN1968L Scaled WFC F555W to reconcile with Wood & Andrews (1974) Accurate to within 1 RA 13:37: and Dec -21:59:59.65

25 Concluding WFC3 has already proven invaluable to our analysis of supernovae Soon to be applied to CMEs Showed a distinction between nuclear SNR and those in the Disc Discovered the location of SN1968L

26 Sources All pictures not otherwise marked sourced by Rogier Windhorst at: