JETS AND WIDE-ANGLE OUTFLOWS IN CEPHEUS E: NEW EVIDENCE FROMSPITZER

Abstract

Outflows and jets are believed to play a crucial role in determining the mass of the central protostar and its planetforming disk by virtue of their ability to transport energy, mass, and momentum of the surrounding material, and thus terminate the infall stage in star and disk formation. In some protostellar objects both wide-angle outflows and collimated jets are seen, while in others only one is observed. Spitzer provides unprecedented sensitivity in the infrared to study both the jet and outflow features. Here, we use HiRes deconvolution to improve the visualization of spatial morphology by enhancing resolution (to subarcsecond levels in the Infrared Array Camera (IRAC) bands) and removing the contaminating sidelobes from bright sources. We apply this approach to study the jet and outflow features in Cep E, a young, energetic Class 0 protostar. In the reprocessed images we detect (1) wide-angle outflow seen in scattered light, (2) morphological details on at least 29 jet-driven bow shocks and jet heads or knots, (3) three compact features in 24 μm continuum image as atomic/ionic line emission coincident with the jet heads, and (4) a flattened ∼35 size protostellar envelope seen against the interstellar background polycyclic aromatic hydrocarbon emission as an absorption band across the protostar at 8 μm. By separating the protostellar photospheric scattered emission in the wide-angle cavity from the jet emission we show that we can study directly the scattered light spectrum. We present the H 2 emission line spectra, as observed in all IRAC bands, for 29 knots in the jets and bow shocks and use them in the IRAC color-color space as a diagnostic of the thermal gas in the shocks driven by the jets. The data presented here will enable detailed modeling of the individual shocks retracing the history of the episodic jet activity and the associated accretion on to the protostar. The Spitzer data analysis presented here shows the richness of its archive as a resource to study the jet/outflow features in H 2 and scattered light in a large homogeneous sample.

Atomic jet from SMM1 (FIRS1) in Serpens uncovers protobinary companion

“…4) is dominated by the [SI] and [FeII] lines encompassed within the band (Velusamy et al 2007(Velusamy et al , 2011. At an angular resolution of 5 , the Mosaic image is in excellent agreement with the line-map morphologies presented in Fig.…”

Identifying Type IIn supernova progenitors in our Galaxy: the circumstellar environment of the Galactic luminous blue variable candidate Gal 026.47+0.02

“…It also allows a resolution enhancement (HiRes) of the final image, by removing its effect from the data in the deconvolution process. A similar method has been applied, quite successfully, to the Spitzer data of young stellar outflows such as HH 46/47 (Noriega‐Crespo et al ; Velusamy, Langer & Marsh ), Cep E (Moro‐Martín et al ; Noriega‐Crespo et al ; Velusamy et al ) and HH 1/2 (Noriega‐Crespo & Raga ). On the IRAC images, the HiRes processing enhances the angular resolution from the standard ∼2 arcsec to ∼0.6–0.8 arcsec (Velusamy et al ; Noriega‐Crespo & Raga ).…”

Proper motions of young stellar outflows in the mid-infrared with Spitzer II HH 377/Cep E

“…Figure 1 shows a comparison of the Palomar 2.12 μm continuum subtracted image with that at 4.5 μm from Noriega-Crespo et al (2004b). Among some of the small obvious differences are the lack of H 2 vibrational emission on the same region where there is a 'wide angle' cone at 4.5 μm (Velusamy et al 2011), which appears to be scattered light by small dust particles; and the emission at 2.12 μm on the south lobe that fits within these 'cones' and reaches further into the IRAS 23011 + 6126 central source. Other than these differences, the knots that we have…”

“…In order to achieve as high a resolution as possible, we have employed a high angular resolution enhancement of the IRAC images, reaching a resolution of ″ 0.6 -″ 0.8 (see Velusamy et al 2007,Velusamy et al 2008,Velusamy et al 2014. Such an enhancement has recently been successfully applied to IRAC images of Cep E (Velusamy et al 2011). Finally, given that observationally there is a tremendous morphological similarity between the mid-IR and NIR emission (Noriega-Crespo et al 2004b), we expand the study to include some ground based H 2 2.12 μm NIR data that allows us to extend the time baseline of the observations to ∼16 yr (table 1).…”