A search for T Tauri stars based on the IRAS point source catalog.

Gregorio-Hetem, J.; Lépine, J. R. D.; Quast, G. R.; Torres, C. A. O.; Reza, R. de la

doi:10.1086/116082

Cited by 189 publications

(190 citation statements)

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“…We obtained EW(Hα) = −41.05 ± 0.09 Å, which is similar to the value reported by Mamajek et al (2002), but lower than that measured by Gregorio-Hetem et al (1992), who found EW(Hα) = −47 Å. This variation of 6 Å in observations obtained ∼10 yr apart is not very high if compared e.g.…”

Section: Hα Line and Accretion Ratesupporting

confidence: 84%

“…Like TW Hya, MP Mus also exhibits evidence of cool plasma at high density (n e ≈ 5 × 10 11 cm −3 , Argiroffi et al 2007). While it is certain that MP Mus is a CTTS (Hα equivalent width is ∼47 Å, Gregorio-Hetem et al 1992), its mass accretion rate is not known. The accretion rate is fundamental for studying the relation between accretion and soft X-ray emission, and we evaluate it in Sect.…”

Section: Targetsmentioning

confidence: 99%

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X-ray optical depth diagnostics of T Tauri accretion shocks

Argiroffi

Maggio

Peres

et al. 2009

A&A

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Context. In classical T Tauri stars, X-rays are produced by two plasma components: a hot low-density plasma, with frequent flaring activity, and a high-density lower temperature plasma. The former is coronal plasma related to the stellar magnetic activity. The latter component, never observed in non-accreting stars, could be plasma heated by the shock formed by the accretion process. However its nature is still being debated. Aims. Our aim is to probe the soft X-ray emission from the high-density plasma component in classical T Tauri stars to check whether this plasma is heated in the accretion shock or whether it is coronal plasma. Methods. High-resolution X-ray spectroscopy allows us to measure individual line fluxes. We analyze X-ray spectra of the classical T Tauri stars MP Muscae and TW Hydrae. Our aim is to evaluate line ratios to search for optical depth effects, which are expected in the accretion-driven scenario. We also derive the plasma emission measure distributions EMD, to investigate whether and how the EMD of accreting and non accreting young stars differ. The results are compared to those obtained for the non-accreting weakline T Tauri star TWA 5. Results. We find evidence of resonance scattering in the strongest lines of MP Mus, supporting the idea that soft X-rays are produced by plasma heated in the accretion shock. We also find that the EMD of MP Mus has two peaks: a cool peak at temperatures expected for plasma heated in the accretion shock, and a hot peak typical of coronal plasma. The shape of the EMD of MP Mus appears to be the superposition of the EMD of a pure coronal source, like TWA 5, and an EMD alike that of TW Hya, which is instead dominated by shock-heated plasma.

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Section: Hα Line and Accretion Ratesupporting

confidence: 84%

Section: Targetsmentioning

confidence: 99%

X-ray optical depth diagnostics of T Tauri accretion shocks

Argiroffi

Maggio

Peres

et al. 2009

A&A

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“…The 800 μm flux measured for HD 141569 (red marker) at CSO (Walker & Butner 1995) has been left out of the fit since it is probably incorrect. References: HD 105 (Moór et al 2006;Hillenbrand et al 2008;Carpenter et al 2005;Cutri et al 2003); HD 21997 (Moór et al 2006;Williams & Andrews 2006;Cutri et al 2003); HD 30447 (Moór et al 2006;Cutri et al 2003); HD 95086 (Chen et al 2006;Cutri et al 2003); HD 98800 (Low et al 2005;Schütz et al 2005;Mannings & Barlow 1998;Cutri et al 2003;Walker & Heinrichsen 2000;Gregorio-Hetem et al 1992;Garcia-Lario et al 1990;Sylvester et al 1996;Cieza 2008;Sylvester et al 2001); HD 109573 (Moór et al 2006;Sheret et al 2004;Barrado Y Navascués 2006;Cutri et al 2003;Low et al 2005;Jura et al 1995;Telesco et al 2000;Jura et al 1993;Fajardo-Acosta et al 1998;Wahhaj et al 2005); HD 131835 (Moór et al 2006;Cutri et al 2003); HD 141569 (Sylvester et al 2001(Sylvester et al , 1996Beichman et al 1988;Walker & Butner 1995;Sheret et al 2004); HD 152404 (Chen et al 2005;…”

Section: Spectral Energy Distributionsmentioning

confidence: 99%

Kuiper belts around nearby stars

Nilsson

Liseau

Brandeker

et al. 2010

A&A

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Context. The existence of dusty debris disks around a large fraction of solar type main-sequence stars, inferred from excess far-IR and submillimetre emission compared to that expected from stellar photospheres, suggests that leftover planetesimal belts analogous to the asteroid-and comet reservoirs of the solar system are common. Aims. Sensitive submillimetre observations are essential to detect and characterise cold extended dust originating from collisions of small bodies in disks, belts, or rings at Kuiper-belt distances (30-50 AU or beyond). Measurements of the flux densities at these wavelengths will extend existing IR photometry and permit more detailed modelling of the Rayleigh-Jeans tail of the disks spectral energy distribution (SED), effectively constraining dust properties and disk extensions. By observing stars spanning from a few up to several hundred Myr, the evolution of debris disks during crucial phases of planet formation can be studied. Methods. We observed 22 exo-Kuiper-belt candidates at 870 μm, as part of a large programme with the LABOCA bolometer at the APEX telescope. Dust masses (or upper limits) were calculated from integrated 870 μm fluxes, and fits to the SED of detected sources revealed the fractional dust luminosities f dust , dust temperatures T dust , and power-law exponents β of the opacity law. Results. A total of 10 detections with at least 3σ significance were made, out of which five (HD 95086, HD 131835, HD 161868, HD 170773, and HD 207129) have previously never been detected at submillimetre wavelengths. Three additional sources are marginally detected with >2.5σ significance. The best-fit β parameters all lie between 0.1 and 0.8, in agreement with previous results indicating the presence of significantly larger grains than those in the ISM. From our relatively small sample we estimate f dust ∝ t −α , with α ∼ 0.8−2.0, and identify an evolution of the characteristic radial dust distance R dust that is consistent with the t 1/3 increase predicted from models of self-stirred collisions in debris disks.

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“…PDS 66, also known as MP Mus and Hen 3-892, is a K1 IVe classical T Tauri star (cTTS) and a member of Lower Centaurus Crux (Gregorio-Hetem et al 1992;Mamajek et al 2002). It exhibits excess infrared emission at λ > 3 μm that has been interpreted as arising from a primordial circumstellar disk (e.g., Silverstone et al 2006;Hillenbrand et al 2008).…”

Section: Pds 66mentioning

confidence: 99%

Mid-infrared observations of the circumstellar disks around PDS 66 and CRBR 2422.8-3423

Gräfe¹,

Wolf²

2013

A&A

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Aims. We present mid-infrared observations and photometry of the circumstellar disks around PDS 66 and CRBR 2422.8-3423, obtained with VISIR/VLT in the N band and for the latter also in the Q band. Our aim is to resolve the inner regions of these protoplanetary disks, which carry potential signatures of intermediate or later stages of disk evolution and ongoing planet formation. Methods. We determined the radial brightness profiles of our target objects and the corresponding PSF reference that were observed before and after our target objects. Background standard deviations, the standard errors, and the seeing variations during the observations were considered. Adopting a simple radiative transfer model based on parameters taken from previous studies, we derived constraints on the inner-disk hole radius of the dust disk. Results. Neither of the circumstellar disks around our science targets are spatially resolved in our observations. However, we are able to constrain the inner-disk hole radius to <15.0 +0.5 −0.5 AU and <10.5 +0.5 −1.0 AU for PDS 66 and CRBR 2422.8-3423, respectively. The photometry we performed yields N-band flux densities of 599 ± 8 mJy for PDS 66 and 130 ± 14 mJy for CRBR 2422.8-3423, as well as a Q-band flux density of 858 ± 109 mJy for CRBR 2422.8-3423.

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A search for T Tauri stars based on the IRAS point source catalog.

Cited by 189 publications

References 0 publications

X-ray optical depth diagnostics of T Tauri accretion shocks

X-ray optical depth diagnostics of T Tauri accretion shocks

Kuiper belts around nearby stars

Mid-infrared observations of the circumstellar disks around PDS 66 and CRBR 2422.8-3423

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