Transcript Hubble Science Briefing: NGC 2174, 24th Anniversary

Hubble Science Briefing
The “Monkey’s Tooth?”
Hubble’s new infrared view
of a star-forming pillar
April 3, 2014
Zolt Levay ・ Hubble
Heritage STScI
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NGC 2174
Hubble’s 24th Anniversary
 Choosing the target
 Context, nomenclature
 Observation planning
 Observation timeline
 Data
 Image features
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WFPC2 2001
Yurij Tukachev
Hubble’s Hidden Treasures
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Location on the sky
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Zoom in to NGC 2174
Digitized Sky Survey red+blue
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Star-forming cloud NGC 2174
SH 2-252
NGC 2174
HII (ionized) region
NGC 2175
Open (galactic) cluster
Digitized Sky Survey red+blue
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The monkey head?
Photo: J-P Metsavainio
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The monkey head?
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The monkey’s tooth?
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Visible — WFPC2 — 2001
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Infrared — WFC3 — 2014
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Visible vs. IR
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Observation planning
 Orbits
 Pointing/mosaic
 Instruments, filters
 Exposure time
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Observation planning — pointing
Astronomer’s Proposal Tool (APT), Aladin
2x2 mosaic
ACS/WFC
parallel
WFC3/IR
Digitized Sky Survey (DSS) image
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Observation planning — filters
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Observation planning — visibility
Astronomer’s Proposal Tool (APT)
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Observation planning — orbit
Astronomer’s Proposal Tool (APT)
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Data — first visits
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Data — F105W mosaic
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Data — replacement visits
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Data — replacement tiles
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Data — mosaics
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Apply color
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Color composite
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Factoids
 Name: NGC 2174-75, Monkey Head Nebula,
Sharpless 2-252 (refers to larger nebula)
 Constellation: Orion
 Coordinates: R.A. 06h 09m 10s, Dec. +20° 27′20″
 Distance: 6,400 light-years, 2 kiloparsecs (~5x M42)
 Instrument: HST WFC3/IR
 Observation date: February 7-24, 2014
 Wavelength: 1,050-1,600 nm (1.05-1.60 μm)
 Exposure: 25-35 min./filter/pointing
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Image features — detail
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Image features — detail
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Image features
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Distinctive features in the image
• Many more stars are apparent in the IR
• Several small knots (red markers) are seen completely or nearly separated from
the main body of the pillar feature. As the gas and dust are eroded and evaporated
from the nebula, denser areas remain as islands, some of which may have enough
density to collapse into stars.
• At the top of one of the sub-pillars there appears to be a proto-stellar jet (yellow
marker), the signature of early star formation. Jets appear in many star-forming
regions such as this, sometimes apparent in visible light, sometimes only appearing
in the IR. Higher resolution (JWST) imaging or spectroscopy would be needed to
confirm that this is a jet.
• Many galaxies (green markers) appear in the IR image, which are totally obscured in
visible light. We can conclude that this region of space is much more transparent at
infrared wavelengths.
• Filaments of gas (blue markers) appear to be streaming from the surface of the
denser portion of the pillar. The hot stars sculpting the material are heating and
evaporating the gas and dust at the surface, and this material is moving away from
the denser material, possibly under the influence of magnetic fields.
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Hubble Heritage
Zolt Levay
Carol Christian
Lisa Frattare
Mario Livio
Jennifer Mack
Max Mutchler
Shelly Meyett
Keith Noll
Josh Sokol
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