Pre- And Post-Burst Radio Observations of the Class 0 Protostar Hops 383 in Orion

Galván-Madrid, Roberto; Rodrı́guez, Luis F.; Liu, Hauyu Baobab; Costigan, G.; Palau, Aina; Zapata, Luis A.; Loinard, Laurent

doi:10.1088/2041-8205/806/2/l32

Cited by 19 publications

(21 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Assuming a constant velocity, the angular distance of ∼16 between HOPS 383 and this emission knot corresponds to a kinematical timescale of ∼180 ± 100 yr. The proper motion direction is consistent with the orientation of the outburst nebula, the 12 CO blueshifted outflow (Feddersen et al 2020), and the position angle of the binary radio counterpart of HOPS 383 at 4 cm (Galván-Madrid et al 2015). We note that the unresolved 3 cm counterpart (Rodríguez et al 2017) corresponds to the faint northwest component at 4 cm, JVLA-NW, which suggests that JVLA-NW would be the base of the radio thermal jet launched by HOPS 383, whereas the brighter southeast component at 4 cm, JVLA-SE, would be an emission knot along this thermal jet (Fig.…”

Section: Near-infrared Resultssupporting

confidence: 77%

“…The blue pluses are radio sources (Galván-Madrid et al 2015;Rodríguez et al 2017). The blue and green arrows show the direction of the thermaljet candidate and the proper motion of the H 2 emission knot SMZ 1-2B, respectively.…”

Section: Observationsmentioning

confidence: 99%

“…1b and c were determined from the pixel maximums in Fig. 1 of Galván-Madrid et al (2015) converted to grayscale, assuming a J2000 world coordinate system, with positional errors estimated using FWHM/(2…”

Section: C3 Astrometrymentioning

confidence: 99%

See 2 more Smart Citations

Evidence for magnetic activity at starbirth: a powerful X-ray flare from the Class 0 protostar HOPS 383

Grosso

Hamaguchi

Principe

et al. 2020

A&A

View full text Add to dashboard Cite

Context. Class 0 protostars represent the earliest evolutionary stage of solar-type stars, during which the majority of the system mass resides in an infalling envelope of gas and dust and is not yet in the central, nascent star. Although X-rays are a key signature of magnetic activity in more evolved protostars and young stars, whether such magnetic activity is present at the Class 0 stage is still debated. Aims. We aim to detect a bona fide Class 0 protostar in X-rays. Methods. We observed HOPS 383 in 2017 December in X-rays with the Chandra X-ray Observatory (∼84 ks) and in near-infrared imaging with the Southern Astrophysical Research telescope. Results. HOPS 383 was detected in X-rays during a powerful flare. This hard (E > 2 keV) X-ray counterpart was spatially coincident with the northwest 4 cm component of HOPS 383, which would be the base of the radio thermal jet launched by HOPS 383. The flare duration was ∼3.3 h; at the peak, the X-ray luminosity reached ∼4 × 1031 erg s−1 in the 2−8 keV energy band, a level at least an order of magnitude larger than that of the undetected quiescent emission from HOPS 383. The X-ray flare spectrum is highly absorbed (NH ∼ 7 × 1023 cm−2), and it displays a 6.4 keV emission line with an equivalent width of ∼1.1 keV, arising from neutral or low-ionization iron. Conclusions. The detection of a powerful X-ray flare from HOPS 383 constitutes direct proof that magnetic activity can be present at the earliest formative stages of solar-type stars.

show abstract

Section: Near-infrared Resultssupporting

confidence: 77%

Section: Observationsmentioning

confidence: 99%

See 1 more Smart Citation

Evidence for magnetic activity at starbirth: a powerful X-ray flare from the Class 0 protostar HOPS 383

Grosso

Hamaguchi

Principe

et al. 2020

A&A

View full text Add to dashboard Cite

show abstract

“…Clearly, something is strongly suppressing the ionized jet activity in FU Ori. We also refer to the report of no enhancement of thermal radio jet emission from the recent Class 0 FU Orionis outburst of HOPS 383 (Galván-Madrid et al 2015). also reported that the radio emission of Class 0/I objects may be bimodal, while the exact reason for such radio flux bimodality is not yet certain.…”

Section: Resultsmentioning

confidence: 88%

A concordant scenario to explain FU Orionis from deep centimeter and millimeter interferometric observations

Liu

Vorobyov

Dong

et al. 2017

A&A

Self Cite

View full text Add to dashboard Cite

Aims. The aim of this work is to constrain properties of the disk around the archetype FU Orionis object, FU Ori, with as good as ∼25 au resolution. Methods. We resolved FU Ori at 29-37 GHz using the Karl G. Jansky Very Largy Array (JVLA) in the A-array configuration, which provided the highest possible angular resolution to date at this frequency band (∼0 ′′ .07). We also performed complementary JVLA 8-10 GHz observations, the Submillimeter Array (SMA) 224 GHz and 272 GHz observations, and compared with archival Atacama Large Millimeter Array (ALMA) 346 GHz observations to obtain the spectral energy distributions (SEDs). Results. Our 8-10 GHz observations do not find evidence for the presence of thermal radio jets, and constrain the radio jet/wind flux to at least 90 times lower than the expected value from the previously reported bolometric luminosity-radio luminosity correlation. The emission at frequencies higher than 29 GHz may be dominated by the two spatially unresolved sources, which are located immediately around FU Ori and its companion FU Ori S, respectively. Their deconvolved radii at 33 GHz are only a few au, which is two orders of magnitude smaller in linear scale than the gaseous disk revealed by the previous Subaru-HiCIAO 1.6 µm coronagraphic polarization imaging observations. We are struck by the fact that these two spatially compact sources contribute to over 50% of the observed fluxes at 224 GHz, 272 GHz, and 346 GHz. The 8-346 GHz SEDs of FU Ori and FU Ori S cannot be fit by constant spectral indices (over frequency), although we cannot rule out that it is due to the time variability of their (sub)millimeter fluxes. Conclusions. The more sophisticated models for SEDs considering the details of the observed spectral indices in the millimeter bands suggest that the >29 GHz emission is contributed by a combination of free-free emission from ionized gas, and thermal emission from optically thick and optically thin dust components. We hypothesize that dust in the innermost parts of the disks ( 0.1 au) has been sublimated, and thus the disks are no more well shielded against the ionizing photons. The estimated overall gas and dust mass based on SED modeling, can be as high as a fraction of a solar mass, which is adequate for developing disk gravitational instability. Our present explanation for the observational data is that the massive inflow of gas and dust due to disk gravitational instability or interaction with a companion/intruder, was piled up at the few au scale due to the development of a deadzone with negligible ionization. The piled up material subsequently triggered the thermal instability and the magnetorotational instability when the ionization fraction in the inner sub-au scale region exceeded a threshold value, leading to the high protostellar accretion rate.

show abstract

“…For example, the infrared source HOPS 383 in Orion was reported to have a large bolometric luminosity increase between (Safron et al 2015, while the radio continuum monitoring at several epochs before and after the outburst (from 1998 to 2014) shows no significant variation in the flux density (Galván-Madrid et al 2015). Ellerbroek et al (2014) could not establish a relation between outflow and accretion variability in the Herbig Ae/Be star HD 163296, the former being measured from proper motions and radial velocities of the jet knots, whereas the latter was measured from near-infrared photometric and Brγ variability.…”

Section: Variabilitymentioning

confidence: 99%

Radio jets from young stellar objects

Anglada

Rodrı́guez²,

Carrasco-González³

2018

Astron Astrophys Rev

Self Cite

137

151

View full text Add to dashboard Cite

Jets and outflows are ubiquitous in the process of formation of stars since outflow is intimately associated with accretion. Free-free (thermal) radio continuum emission in the centimeter domain is associated with these jets. The emission is relatively weak and compact, and sensitive radio interferometers of high angular resolution are required to detect and study it. One of the key problems in the study of outflows is to determine how they are accelerated and collimated. Observations in the cm range are most useful to trace the base of the ionized jets, close to the young central object and the inner parts of its accretion disk, where optical or near-IR imaging is made difficult by the high extinction present. Radio recombination lines in jets (in combination with proper motions) should provide their 3D kinematics at very small scale (near their origin). Future instruments such as the Square Kilometre Array (SKA) and the Next Generation Very Large Array (ngVLA) will be crucial to perform this kind of sensitive observations. Thermal jets are associated with both high and low mass protostars and possibly even with objects in the substellar domain. The ionizing mechanism of these radio jets appears to be related to shocks in the associated outflows, as suggested by the observed correlation between the centimeter luminosity and the outflow momentum rate. From this correlation and that of the centimeter luminosity with the bolometric luminosity of the system it will be possible to discriminate between unresolved HII regions and jets, and to infer additional physical properties of the embedded objects. Some jets associated with young stellar objects (YSOs) show indications of nonthermal emission (negative spectral indices) in part of their lobes. Linearly polarized synchrotron emission has been found in the jet of HH 80-81, allowing one to measure the direction and intensity of the jet magnetic field, a key ingredient to determine the collimation and ejection mechanisms. As only a fraction of the emission is polarized, very sensitive observations such as those that will be feasible with the interferometers previously mentioned are required to perform studies in a large sample of sources. Jets are present in many kinds of astrophysical scenarios. Characterizing radio jets in YSOs, where thermal emission allows one to determine their physical conditions in a reliable way, would also be useful in understanding acceleration and collimation mechanisms in all kinds of astrophysical jets, such as those associated with stellar and supermassive black holes and planetary nebulae.

show abstract

Pre- And Post-Burst Radio Observations of the Class 0 Protostar Hops 383 in Orion

Cited by 19 publications

References 39 publications

Evidence for magnetic activity at starbirth: a powerful X-ray flare from the Class 0 protostar HOPS 383

Evidence for magnetic activity at starbirth: a powerful X-ray flare from the Class 0 protostar HOPS 383

A concordant scenario to explain FU Orionis from deep centimeter and millimeter interferometric observations

Radio jets from young stellar objects

Contact Info

Product

Resources

About