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J/ApJ/848/18   High-res. spectroscopic obs. of 2 Herbig stars   (Aarnio+, 2017)

High-cadence, high-resolution spectroscopic observations of Herbig stars HD 98922 and V1295 Aquila. Aarnio A.N., Monnier J.D., Harries T.J., Kraus S., Calvet N., Acreman D., Che X. <Astrophys. J., 848, 18-18 (2017)> =2017ApJ...848...18A (SIMBAD/NED BibCode)
ADC_Keywords: Spectra, optical; Stars, pre-main sequence Keywords: stars: formation; stars: individual: (HD 98922, V1295 Aql); stars: pre-main sequence; stars: variables: T Tauri, Herbig Ae/Be Abstract: Recent observational work has indicated that mechanisms for accretion and outflow in Herbig Ae/Be star-disk systems may differ from magnetospheric accretion (MA) as it is thought to occur in T Tauri star-disk systems. In this work, we assess the temporal evolution of spectral lines probing accretion and mass loss in Herbig Ae/Be systems and test for consistency with the MA paradigm. For two Herbig Ae/Be stars, HD 98922 (B9e) and V1295 Aql (A2e), we have gathered multi-epoch (∼years) and high-cadence (∼minutes) high-resolution optical spectra to probe a wide range of kinematic processes. Employing a line equivalent width evolution correlation metric introduced here, we identify species co-evolving (indicative of common line origin) via novel visualization. We interferometrically constrain often problematically degenerate parameters, inclination and inner-disk radius, allowing us to focus on the structure of the wind, magnetosphere, and inner gaseous disk in radiative transfer models. Over all timescales sampled, the strongest variability occurs within the blueshifted absorption components of the Balmer series lines; the strength of variability increases with the cadence of the observations. Finally, high-resolution spectra allow us to probe substructure within the Balmer series' blueshifted absorption components: we observe static, low-velocity features and time-evolving features at higher velocities. Overall, we find the observed line morphologies and variability are inconsistent with a scaled-up T Tauri MA scenario. We suggest that as magnetic field structure and strength change dramatically with increasing stellar mass from T Tauri to Herbig Ae/Be stars, so too may accretion and outflow processes. Description: From 2006 to 2013, we conducted an optical spectroscopic observational campaign of a sample of ∼60 HAeBe stars. Over the course of gathering data, we observed 13 objects at multiple epochs; 2 of these, V1295 Aql and HD 98922, were followed-up on in 2013 with high-cadence time-series observations. Our optical spectra were taken with MIKE, the Magellan Inamori Kyocera Echelle (Las Campanas Observatory), a cross-dispersed double echelle spectrograph. The blue side of MIKE covers a ∼3200-5000Å range, and the red chip spans ∼4900-10000Å; using the narrowest slit, 0.35", the resolving powers of the blue and red sides are R∼80000 and R∼65000, respectively. Objects: ------------------------------------------------------------------ RA (ICRS) DE Designation(s) Per ------------------------------------------------------------------ 11 22 31.67 -53 22 11.5 HD 98922 = TYC 8617-657-1 (P=4-8) 20 03 02.51 +05 44 16.7 V1295 Aql = HD 190073 (P=32) ------------------------------------------------------------------ File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 94 451 *Time series observing log with MIKE (the Magellan Inamori Kyocera Echelle)
Note on table1.dat: All data are MIKE spectra, unless otherwise indicated (i.e. 12 ESO -UVES and -HARPS archival spectra). Time-series spectra were generally taken in sets of four integrations, with ThAr lamps taken between sets.
See also: J/A+A/599/A85 : Structure of Herbig AeBe disks at mas scale (Lazareff+, 2017) J/A+A/586/A47 : Accretion process in NGC 2264 (Sousa+, 2016) J/other/NewA/44.1 : IR photometric study of Herbig Ae/Be stars (Chen+, 2016) J/ApJ/698/2031 : Polarimetry of HAeBe stars (Rodrigues+, 2009) J/ApJ/653/657 : Spectroscopic obs. of Herbig Ae/Be stars (Manoj+, 2006) J/A+A/442/1127 : Library of 2500-10500Å synthetic spectra (Munari+, 2005) J/ApJ/606/L73 : CO emission of 5 Herbig Ae stars (Blake+, 2004) J/AJ/126/2971 : UBVRI photometry of 131 Herbig Ae/Be (Vieira+, 2003) J/A+A/378/116 : Classification & vsini of Vega-type & PMS stars (Mora+, 2001) J/A+A/361/1143 : Proper motions of PMS stars (Teixeira+ 2000) J/AJ/118/1043 : Herbig Ae/Be stars catalog (Herbst+, 1999) J/A+AS/104/315 : Member of Herbig Ae/Be stellar group (The+ 1994) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 11 A11 "Y/M/D" Date of the observation 13- 49 A37 --- Desc Description data 51- 59 A9 --- Name Star name ("HD 98922" or "V1295 Aql") 61- 71 A11 "h:m:s" Obs.time UT time of the observation 73- 84 A12 --- Filter Filter use or wavelength range if spectra (mainly B, R, or 3044-3916AA, 3732-4999AA, 3780-6911 4726-6835AA, 6650-10250AA) 86- 88 I3 s Exp [15/600] Integration time 90- 94 F5.3 --- Airmass [1/2.6]? Airmass
History: From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 07-Jun-2018
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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