YSO Jets in the Galactic Plane from UWISH2. IV. Jets and Outflows in Cygnus-X

Makin, S. V.; Froebrich, D.

doi:10.3847/1538-4365/aa8862

Cited by 22 publications

(24 citation statements)

References 57 publications

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“…The recurrence timescale from our study is larger than the time between ejection events of ≃ 1000 years determined from the observed gaps between H 2 knots along jets from YSOs (Ioannidis & Froebrich 2012;Froebrich & Makin 2016;Makin & Froebrich 2018) and the 100 year timescale observed in MNors by (Contreras Peña et al 2017a). However this is not surprising as H 2 jets likely trace the accretion related events during the class I phase (Ioannidis & Froebrich 2012) and that the young eruptive variables in Contreras Peña et al (2017a) are biased towards class I YSOs.…”

Section: Other Observational Evidencementioning

confidence: 53%

Determining the recurrence time-scale of long-lasting YSO outbursts

Peña

Naylor

Morrell

2019

Monthly Notices of the Royal Astronomical Society

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We have determined the rate of large accretion events in class I and II young stellar objects (YSOs) by comparing the all-sky digitised photographic plate surveys provided by SuperCOSMOS with the latest data release from Gaia (DR2). The long mean baseline of 55 years along with a large sample of class II YSOs (≃15,000) allows us to study approximately 1 million YSO-years. We find 139 objects with ∆R ≥ 1 mag, most of which are found at amplitudes between 1 and 3 mag. The majority of YSOs in this group show irregular variability or long-lasting fading events, which is best explained as hot spots due to accretion or by variable extinction. There is a tail of YSOs at ∆R ≥ 3 mag and they seem to represent a different population. Surprisingly many objects in this group show high-amplitude irregular variability over timescales shorter than 10 years, in contrast with the view that high-amplitude objects always have long outbursts. However, we find 6 objects that are consistent with undergoing large, long lasting accretion events, 3 of them previously unknown. This yields an outburst recurrence timescale of 112 kyr, with a 68% confidence interval [74 to 180] kyr. This represents the first robust determination of the outburst rate in class II YSOs and shows that YSOs in their planet-forming stage do in fact undergo large accretion events, and with timescales of ≃100,000 years. In addition, we find that outbursts in the class II stage are ≃10 times less frequent than during the class I stage.

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Section: Other Observational Evidencementioning

confidence: 53%

Determining the recurrence time-scale of long-lasting YSO outbursts

Peña

Naylor

Morrell

2019

Monthly Notices of the Royal Astronomical Society

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“…Because fluorescence excited features appear brownish in the JKH2 RGB images as the J-and K-band continuum filters contain additional excited emission-lines (e.g. Makin & Froebrich 2018). Similarly, 8 µm IRAC band contains the 7.7 and 8.8 µm emission features commonly attributed to polycyclic aromatic hydrocarbons (PAH) molecules (Reach Povich et al 2007).…”

Section: Identification Of the Outflows And Outflow Driving Sourcesmentioning

confidence: 99%

“…In this regard, the UKIRT Widefield Infrared Survey for H2 (UWISH2; Froebrich et al 2011) conducted with United Kingdom Infrared Telescope (UKIRT) at 2.12 µm (H2 ν = 1-0 S(1)) has opened a new avenue to search for outflows from the YSOs (e.g. Ioannidis & Froebrich 2012a,b;Froebrich & Makin 2016;Makin & Froebrich 2018), even possibly from low-mass YSOs (e.g. Ioannidis & Froebrich 2012b).…”

Section: Introductionmentioning

confidence: 99%

YSO jets in the Galactic plane from UWISH2 – V. Jets and outflows in M17

Samal

Chen

Takami

et al. 2018

Monthly Notices of the Royal Astronomical Society

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Jets and outflows are the first signposts of stellar birth. Emission in the H 2 1-0 S(1) line at 2.122 µm is a powerful tracer of shock excitation in these objects. Here we present the analysis of 2.0 × 0.8 deg 2 data from the UK Widefield Infrared Survey for H 2 (UWISH2) in the 1-0 S(1) line to identify and characterize the outflows of the M17 complex. We uncover 48 probable outflows, of which, 93 per cent are new discoveries. We identified driving source candidates for 60 per cent of the outflows. Among the driving source candidate YSOs: 90 per cent are protostars and the reminder 10 per cent are Class II YSOs. Comparing with results from other surveys, we suggest that H 2 emission fades very quickly as the objects evolve from protostars to premain-sequence stars. We fit SED models to 14 candidate outflow driving sources and conclude that the outflows of our sample are mostly driven by moderate-mass YSOs that are still actively accreting from their protoplanetary disc. We examined the spatial distribution of the outflows with the gas and dust distribution of the complex, and observed that the filamentary dark-cloud "M17SWex" located at the south-western side of the complex, is associated with a greater number of outflows. We find our results corroborate previous suggestions, that in the M17 complex, M17SWex is the most active site of star formation. Several of our newly identified outflow candidates are excellent targets for follow up studies to better understand very early phase of protostellar evolution.

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“…Stellar winds and outflows are commonly detected by shockexcited H 2 emission among Class I objects (Makin & Froebrich 2018). In long slit spectra, extended H 2 emission around YSOs is associated with a disc wind, outflow, HH object, or bow shock (Davis et al 2001;Takami et al 2004;Bally et al 2007;Agra-Amboage et al 2014).…”

Section: V815: Launching Of Outflow On a Short Timescalementioning

confidence: 99%

Short- and long-term near-infrared spectroscopic variability of eruptive protostars from VVV

Guo

Lucas

Peña

et al. 2019

Monthly Notices of the Royal Astronomical Society

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Numerous eruptive variable young stellar objects (YSOs), mostly Class I systems, were recently detected by the near-infrared Vista Variables in the Via Lactea (VVV) survey. We present an exploratory near-infrared spectroscopic variability study of 14 eruptive YSOs. The variations were sampled over 1-day and 1 to 2-year intervals and analysed in combination with VVV light curves. CO overtone absorption features are observed on 3 objects with FUor-like spectra: all show deeper absorption when they are brighter. This implies stronger emission from the circumstellar disc with a steeper vertical temperature gradient when the accretion rate is higher. This confirms the nature of fast VVV FUor-like events, in line with the accepted picture for classical FUors. The absence of Brγ emission in a FUor-like object declining to pre-outburst brightness suggests that reconstruction of the stellar magnetic field is a slow process. Within the 1-day timescale, 60% of H 2 -emitting YSOs show significant but modest variation, and 2/6 sources have large variations in Brγ. Over year-long timescales, H 2 flux variations remain modest despite up to 1.8 mag variation in K s . This indicates that emission from the molecular outflow usually arises further from the protostar and is unaffected by relatively large changes in accretion rate on year-long timescales. Two objects show signs of on/off magnetospheric accretion traced by Brγ emission. In addition, a 60% inter-night brightening of the H 2 outflow is detected in one YSO.

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YSO Jets in the Galactic Plane from UWISH2. IV. Jets and Outflows in Cygnus-X

Cited by 22 publications

References 57 publications

Determining the recurrence time-scale of long-lasting YSO outbursts

Determining the recurrence time-scale of long-lasting YSO outbursts

YSO jets in the Galactic plane from UWISH2 – V. Jets and outflows in M17

Short- and long-term near-infrared spectroscopic variability of eruptive protostars from VVV

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