H<sub>2</sub>active jets in the near IR as a probe of protostellar evolution

Garatti, A. Caratti o; Giannini, T.; Nisini, B.; Lorenzetti, D.

doi:10.1051/0004-6361:20054313

Cited by 119 publications

(193 citation statements)

References 63 publications

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“…In general, MHEL properties are consistent with shockheated gas from the inner regions of Herbig-Haro objects or from spatially extended wide-angle winds (Davis et al 2001;Caratti o Garatti et al 2006;Beck et al 2008;Davis et al 2011). The reported gas temperatures and excitation properties of IRS54 are consistent with shock-heated material, as well.…”

Section: Discussionsupporting

confidence: 59%

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Spatially resolved H₂emission from a very low-mass star

Lopez

Garatti

Weigelt

et al. 2013

A&A

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Context. Molecular outflows from very low-mass stars (VLMSs) and brown dwarfs have been studied very little. So far, only a few CO outflows have been observed, allowing us to map the immediate circumstellar environment. Aims. We present the first spatially resolved H 2 emission around IRS54 (YLW 52), a ∼0.1-0.2 M Class I source. Methods. By means of VLT SINFONI K-band observations, we probed the H 2 emission down to the first ∼50 AU from the source.Results. The molecular emission shows a complex structure delineating a large outflow cavity and an asymmetric molecular jet. Thanks to the detection of several H 2 transitions, we are able to estimate average values along the jet-like structure (from source position to knot D) of A V ∼ 28 mag, T ∼ 2000−3000 K, and H 2 column density N(H 2 ) ∼ 1.7 × 10 17 cm −2 . This allows us to estimate a mass loss rate of ∼2 × 10 −10 M yr −1 for the warm H 2 component. In addition, from the total flux of the Br γ line, we infer an accretion luminosity and mass accretion rate of 0.64 L and ∼3 × 10 −7 M yr −1 , respectively. The outflow structure is similar to those found in low-mass Class I and CTTS. However, the L acc /L bol ratio is very high (∼80%), and the mass accretion rate is about one order of magnitude higher when compared to objects of roughly the same mass, pointing to the young nature of the investigated source.

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Section: Discussionsupporting

confidence: 59%

“…In addition, thanks to detecting several H 2 lines, excitation diagrams could be constructed to derive the temperature, H 2 column density, and extinction of the molecular gas (e.g., Caratti o Garatti et al 2006;Garcia Lopez et al 2010). The results are shown in Table 1.…”

Section: Outflow Physics and Morphologymentioning

confidence: 99%

Spatially resolved H₂emission from a very low-mass star

Lopez

Garatti

Weigelt

et al. 2013

A&A

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“…The angular resolution of this image is much (Beltrán et al 2002) overlaid with an IRAC 4.5 μm image. The H 2 emission shows a large number of molecular hydrogen features, many already found by Nisini et al (2001), Reipurth et al (2003), and Caratti o Garatti (2006), whose nomenclature we use and expand. The black crosses show the positions of the 3.1 mm sources, BIMA 1, 2, and 3 from Beltrán et al (2002), and the white one shows the position of the 1.3 mm continuum source C detected by Codella et al (2001). higher than that of Fig.…”

Section: The Title Of the Spitzer Program Is Star Formation In Brightmentioning

confidence: 72%

“…Beltrán et al (2002) have conducted a detailed study of the bipolar outflow associated with the intermediate-mass protostar BIMA 2, and shown that its complex morphology and kinematics are possibly the result of the interaction between the outflow and the dense cores surrounding the protostar. NIR images of the region have also revealed a number of small scale molecular hydrogen and Herbig-Haro (HH) flows Sugitani et al 2002a;Reipurth et al 2003;Caratti o Garatti et al 2006). This evidence of ongoing star-formation activity at the head of the cometary globule, together with the relatively proximity of the region, make IC 1396N one of the best candidates for studying potential sequential star formation.…”

Section: Introductionmentioning

confidence: 99%

The stellar population and complex structure of the bright-rimmed cloud IC 1396N

Beltrán¹,

Massi

López

et al. 2009

A&A

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Context. IC 1396N is a bright-rimmed cloud associated with an intermediate-mass star-forming region, where a number of HerbigHaro objects, H 2 jet-like features, CO molecular outflows, and millimeter compact sources have been observed. Aims. We study the complex structure of the IC 1396N core and the molecular outflows detected in the region in detail and reveal the presence of additional YSOs inside this globule. Methods. We carried out a deep survey of the IC 1396N region in the J, H, K broadband filters and deep high-angular resolution observations in the H 2 narrowband filter with NICS at the TNG telescope. The completeness limits in the 2MASS standard are K s ∼ 17.5, H ∼ 18.5, and J ∼ 19.5. Results. A total of 736 sources have been detected in all three bands within the area where the JHK images overlap. There are 128 sources detected only in HK , 67 detected only in K , and 79 detected only in JH. We found only a few objects exhibiting a near-infrared excess and no clear signs of clustering of sources towards the southern rim. In the case of triggered star formation in the southern rim of the globule, this could be very recent, because it is not shown through Near-Infrared imaging alone. The H 2 emission is complex and knotty and shows a large number of molecular hydrogen features spread over the region, testifying to recent starformation activity throughout the whole globule. This emission is resolved into several chains or groups of knots that sometimes show a jet-like morphology. The shocked cloudlet model scenario previously proposed to explain the V-shaped morphology of the CO molecular outflow powered by the intermediate-mass YSO BIMA 2 seems to be confirmed by the presence of H 2 emission at the position of the deflecting western clump. New possible flows have been discovered in the globule, and some of them could be very long. In particular, the YSO BIMA 3 could be powering an old and poorly collimated outflow.

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“…, H 2 (see, e.g., Hartigan et al 1995;Nisini et al 2002;Caratti o Garatti et al 2006). A few YSOs, namely #2, #3, #11, and #18, also show permitted ionic emission lines (e.g., O i, Fe i, Fe ii, Na i, Mg ii, C i), which are characteristic of active young stars (see, e.g., Hamann & Persson 1992a,b;Kelly et al 1994;Hernández et al 2004), and usually associated with chromospheric activity.…”

Section: Optical and Nir Spectramentioning

confidence: 99%

POISSON project

Garatti

Lopez

Antoniucci

et al. 2012

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Context. Characterising stellar and circumstellar properties of embedded young stellar objects (YSOs) is mandatory for understanding the early stages of the stellar evolution. This task requires the combination of both spectroscopy and photometry, covering the widest possible wavelength range, to disentangle the various protostellar components and activities. Aims. As part of the POISSON project (Protostellar Optical-Infrared Spectral Survey On NTT), we present a multi-wavelength spectroscopic and photometric investigation of embedded YSOs in L 1641, aimed to derive the stellar parameters and evolutionary stages and to infer their accretion properties. Methods. Our multi-wavelength database includes low-resolution optical-IR spectra from the NTT and Spitzer (0.6−40 μm) and photometric data covering a spectral range from 0.4 to 1100 μm, which allow us to construct the YSOs spectral energy distributions (SEDs) and to infer the main stellar parameters (visual extinction, spectral type, accretion, stellar, bolometric luminosity, mass accretion, and ejection rates). Results. The NTT optical-NIR spectra are rich in emission lines, which are mostly associated with YSO accretion, ejection, and chromospheric activities. A few emission lines, prominent ice (H 2 O and CO 2 ), and amorphous silicate absorption features have also been detected in the Spitzer spectra. The SED analysis allows us to group our 27 YSOs into nine Class I, eleven Flat, and seven Class II objects. However, on the basis of the derived stellar properties, only six Class I YSOs have an age of ∼10 5 yr, while the others are older (5 × 10 5 −10 6 yr), and, among the Flat sources, three out of eleven are more evolved objects (5 × 10 6 −10 7 yr), indicating that geometrical effects can significantly modify the SED shapes. Inferred mass accretion rates (Ṁ acc ) show a wide range of values (3.6 × 10 −9 to 1.2 × 10 −5 M yr −1 ), which reflects the age spread observed in our sample well. Average values of mass accretion rates, extinction, and spectral indices decrease with the YSO class. The youngest YSOs have the highestṀ acc , whereas the oldest YSOs do not show any detectable jet activity in either images and spectra. Apart from the outbursting source #25 and, marginally, #20, none of the remaining YSOs is accretion-dominated (L acc > L * ). We also observe a clear correlation among the YSOṀ acc , M * , and age. For YSOs with t > 10 5 yr and 0.4 M ≤ M * ≤ 1.2 M , a relationship betweenṀ acc and t (Ṁ acc ∝ t −1.2 ) has been inferred, consistent with mass accretion evolution in viscous disc models and indicating that the mass accretion decay is slower than previously assumed. Finally, our results suggest that episodic outbursts are required for Class I YSOs to reach typical classical T Tauri stars stellar masses.

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H₂active jets in the near IR as a probe of protostellar evolution

Cited by 119 publications

References 63 publications

Spatially resolved H₂emission from a very low-mass star

Spatially resolved H₂emission from a very low-mass star

The stellar population and complex structure of the bright-rimmed cloud IC 1396N

POISSON project

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H2active jets in the near IR as a probe of protostellar evolution

Cited by 119 publications

References 63 publications

Spatially resolved H2emission from a very low-mass star

Spatially resolved H2emission from a very low-mass star

The stellar population and complex structure of the bright-rimmed cloud IC 1396N

POISSON project

Contact Info

Product

Resources

About

H₂active jets in the near IR as a probe of protostellar evolution

Spatially resolved H₂emission from a very low-mass star

Spatially resolved H₂emission from a very low-mass star