Download presentation
Presentation is loading. Please wait.
Published bySophia Walker Modified over 9 years ago
1
Rachael Ainsworth Dublin Institute for Advanced Studies YERAC 2011
2
16 GHz radio continuum observations of target sample for the e-MERLIN legacy project on the morphology and time evolution of thermal jets associated with low mass young stars (Rodriguez+). I will draw correlations between the radio luminosity and a number of global properties for these systems. These correlations along with the spectral indices for these sources will help place limits on the physical mechanisms responsible for the radio emission. Future work: e-MERLIN
3
Evolutionary Indicators (Hatchell+ 2007) ◦ Bolometric temperature Class 0: T bol < 70 K, Class I: 70 < T bol < 150 K ◦ Ratio of submm to bolometric luminosity L bol /L smm > 3000 ◦ Ratio of Spitzer IRAC to submm emission F 3.6 /F 850 > 0.003
4
A form of thermal emission that comes from gas which has been ionized. Atoms in the gas become ionized when their electrons become stripped or dislodged. This results in charged particles moving around in an ionized gas. As this happens, the electrons are accelerated by the charged particles, and the gas cloud emits radiation continuously. Often called called "free-free" emission because it is produced by free electrons scattering off ions without being captured.
5
S ν = ν 2 S ν = ν 0.6 S ν = ν -0.1 Optically thick Partially optically thick Optically thin
6
Ionized spherical stellar winds (Panagia & Felli 1975) Ionized collimated winds (Reynolds 1986) Both models predict a correlation between the radio luminosity and the rate of stellar mass loss, and α = 0.6, where α is the spectral index defined as
7
L1448, HH 7-11, L1551, L1527, HH 1-2, HH 26 IR, HH 111, NGC 2264, Serpens, L723, L1251
11
(Scaife+ 2011) log[L 1.8 cm (mJy kpc 2 )] = −(1.74 ± 0.18) + (0.51±0.26)log[L bol (L⊙)] log[L 1.8 cm (mJy kpc 2 )] = −1.44 + 0.60log[L bol (L⊙)]
12
(Scaife+ 2011) log[L 1.8 cm (mJy kpc 2 )] = −(2.23 ± 0.65) + (0.68±0.62)log[M env (M⊙)] log[L 1.8 cm (mJy kpc 2 )] = −2.26 + 1.21log[M env (M⊙)]
13
Capabilities include: o Observing bands at 1.3-1.8 GHz, 4-8 GHz, 22-24 GHz o Resolution 10 to 150 mas o Total bandwidth 4 GHz o Sensitivity ~ 1 μJy o Astrometry, polarimetry, spectroscopy o Image the jet launch zone to look for clues as to how jets from young stars are generated. o Measure the strength and direction of the magnetic field in the jet launch zone.
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.