High-resolution polarimetry of Parsamian 21: revealing the structure of an edge-on FU Ori disc★

Kóspál, Á.; Ábrahám, P.; Apai, Dániel; Ardila, D. R.; Grady, C. A.; Henning, Th.; Juhász, A.; Miller, Donald; Moór, A.

doi:10.1111/j.1365-2966.2007.12557.x

Cited by 23 publications

(29 citation statements)

References 63 publications

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“…For example, V2492 Cyg and V346 Nor are known to drive Herbig-Haro objects (HH 569 and HH 57, respectively; see Bally & Reipurth 2003;Reipurth & Wamsteker 1983). On the other hand, OO Ser is associated with outflow activity and shock-excited H 2 emission (Hodapp et al 2012), whereas Parsamian 21 shows Hα knots with dynamical ages of 40-80 years (Staude & Neckel 1992;Kóspál et al 2008). However, it is difficult to associate specific eruptive/outburst events with knots or augmented ejection along the flows.…”

Section: Introductionmentioning

confidence: 99%

LBT/LUCIFER near-infrared spectroscopy of PV Cephei

Garatti

Lopez

Weigelt

et al. 2013

A&A

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Context. Young stellar objects (YSOs) occasionally experience enhanced accretion events, the nature of which is still poorly understood. The discovery of various embedded outbursting YSOs has recently questioned the classical definition of EXors and FUors. Aims. We present a detailed spectroscopic investigation of the young eruptive star PV Cep, to improve our understanding of its nature and characterise its circumstellar environment after its last outburst in 2004. Methods. The analysis of our medium-resolution spectroscopy in the near-infrared (NIR, 0.9-2.35 μm), collected in 2012 at the Large Binocular Telescope with the IR spectrograph LUCIFER, allows us to infer the main stellar parameters (visual extinction, accretion luminosity, mass accretion and ejection rates), and model the inner disc, jet, and wind. Results. The NIR spectrum displays several strong emission lines associated with accretion/ejection activity and circumstellar environment. Our analysis shows that the brightness of PV Cep is fading, as well as the mass accretion rate (2 × 10 −7 M yr −1 in 2012 vs. ∼5 × 10 −6 M yr −1 in 2004), which is more than one order of magnitude lower than in the outburst phase.Among the several emission lines, only the [Fe ii] intensity increased after the outburst. The observed [Fe ii] emission delineates blue-and red-shifted lobes, both with high-and low-velocity components, which trace an asymmetric jet and wind, respectively. The observed emission in the jet has a dynamical age of 7-8 years, indicating that it was produced during the last outburst. The visual extinction decreases moving from the red-shifted (A V (red) = 10.1 ± 0.7 mag) to the blue-shifted lobe (A V (blue) = 6.5 ± 0.4 mag). We measure an average electron temperature of 17 500 K and electron densities of 30 000 cm −3 and 15 000 cm −3 for the blue and the red lobe, respectively. The mass ejection rate in both lobes is ∼1.5 × 10 −7 M yr −1 , approximately matching the high accretion rate observed during and immediately after the outburst (Ṁ out /Ṁ acc ∼ 0.05-0.1). The observed jet/outflow asymmetries are consistent with an inhomogeneous medium. Our modelling of the CO emission hints at a small-scale gaseous disc ring, extending from ∼0.2-0.4 AU to ∼3 AU from the source, with an inner temperature of ∼3000 K. Our H i lines modelling indicates that most of the observed emission comes from an expanding disc wind at T e = 10 000 K. The line profiles are strongly affected by scattering, disc screening, and outflow self-absorption. Conclusions. According to the classical definition, PV Cep is not an EXor object, because it is more massive and younger than typical EXors. Nevertheless, its spectrum shows the signature of an "EXor-like" outburst, suggesting a common origin.

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Section: Introductionmentioning

confidence: 99%

LBT/LUCIFER near-infrared spectroscopy of PV Cephei

Garatti

Lopez

Weigelt

et al. 2013

A&A

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“…This interpretation would be unacceptable if the four classical FUors were the only FUors known, since statistically, this would be highly improbable. However, two sources postulated to be FUors, Par 21 (Staude & Neckel 1992;Kóspál et al 2008) and HH381 IRS (Reipurth & Aspin 1997;T.-Yu. Magakian et al 2011, in preparation), both have bright monopolar cavities seen in reflected light and have inferred inclinations <30…”

Section: Using Hα Fw10% To Deriveṁ Accmentioning

confidence: 99%

The Continuing Outburst of V1647 Orionis: Winter/Spring 2011 Observations

Aspin

2011

The Astronomical Journal

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We present optical and near-IR observations of the young eruptive variable star V1647 Orionis which illuminates McNeil's Nebula. In late 2003, V1647 Ori was observed to brighten by around 5 mag to r = 17.7. In early 2006 the star faded back to its quiescent brightness of r ∼ 23, however in mid-2008 it brightened yet again by ∼5 mag. Our new observations, taken in early 2011, show V1647 Ori to be in an elevated photometric state with an optical brightness similar to the value found at the start of the 2003 and 2008 outbursts. Optical images taken between 2008 and 2011 suggest that the star has remained in outburst from mid-2008 to the present. Hα and the far-red Ca ii triplet lines remain in emission with Hα possessing a significant P Cygni profile. A self-consistent study of the accretion luminosity and rate using data taken in 2004, 2007, 2008, and 2011 indicates that when bright, V1647 Ori has values of 16 ± 2 L and (4 ± 2) × 10 −6 M yr −1 , respectively. We support the premise that the accretion luminosity and rate both declined by a factor of 2-3 during the 5 mag fading in 2007. However, a significant part of the fading was due to either variable extinction or dust reformation. We discuss these new observations in relation to previous published data and the classification schemes for young eruptive variables.

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“…D 'Alessio et al 2005'Alessio et al , 2006Dullemond & Dominik 2005;Dullemond et al 2007;Furlan et al 2008;Meijer et al 2009, for recent work) has provided a sound framework for interpreting observational results. At shorter wavelengths, A&A 511, A10 (2010) high-resolution visible and near-infrared imaging with the Hubble Space Telescope (HST) (Stapelfeldt et al 2003;Coffey et al 2007;Watson & Stapelfeldt 2007), by adaptive optics (Kóspál et al 2008) or by spectroastrometry (Whelan et al 2006) have helped to understand the origin of jets by probing their launch regions in the proximity of the star, allowing a comparison between the observed kinematics and spectral information with the predictions of models.…”

Section: Introductionmentioning

confidence: 99%

High-resolution visible spectroscopy of the jet-driving star Th 28

Comerón¹,

Fernández²

2010

A&A

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Context. We present a study of the extreme T Tauri star Th 28, a young stellar object in the Lupus 3 cloud whose spectrum displays all the varieties of signposts associated with early stellar activity. Th 28 is the driving source of a fast jet, making it a very promising target to study the disk-jet connection. Aims. We try to identify and investigate the different structural components that contribute to the different emission lines in the spectrum of the Th 28 central source. Methods. We obtained high-resolution visible spectroscopy with the UVES spectrograph at the VLT, using the resolved profiles of both permitted and forbidden lines as tracers of gas with different kinematic and physical properties, complemented with other observations from the literature. Results. We identify four distinct structural components that contribute to the visible emission-line spectrum of Th 28. The first one, dominating most of the permitted and forbidden lines, is probably associated with the origin of the outflow that in the past produced the Herbig-Haro objects seen to the west of Th 28. The second one is an uncollimated stellar wind characterized by high excitation and temperature, as shown by the broad profile of the intense [OIII] lines. The third component, traced only by permitted lines, appears as a redshifted tail extending up to radial velocities of +450 km s −1 , which we attribute to magnetospheric accretion. From the latter component we obtain a rough estimate of 0.6−0.9 M for the mass of the central object. Using published equivalent widths of the CaII triplet lines, we estimate an accretion rate of 4.2−6.3 × 10 −8 M yr −1 , comparable to the values inferred for other T Tauri stars of similar mass. The last component, which appears most clearly in the [SII] lines and is hardly seen in any lines other than those of [OI], displays signatures that we interpret as coming from rotation, perhaps formed in a disk atmosphere. Following this interpretation, we estimate a disk central hole of 0.7 AU radius. Conclusions. Even though spatially unresolved, the spectrum of Th 28 is rich in emission lines whose shapes provide important information on the distinct structures where they form. In this way we were able to identify the existence of a stellar wind, an accretion flow, the basis of a collimated outflow, and possibly a rotating disk atmosphere, obtaining rough estimates of basic parameters of the central source and its environment that should be useful for further modeling.

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High-resolution polarimetry of Parsamian 21: revealing the structure of an edge-on FU Ori disc★

Cited by 23 publications

References 63 publications

LBT/LUCIFER near-infrared spectroscopy of PV Cephei

LBT/LUCIFER near-infrared spectroscopy of PV Cephei

The Continuing Outburst of V1647 Orionis: Winter/Spring 2011 Observations

High-resolution visible spectroscopy of the jet-driving star Th 28

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