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J/ApJ/789/L38    LRLL54361 protostar Herschel/PACS fluxes         (Balog+, 2014)

The extraordinary far-infrared variation of a protostar: Herschel/PACS observations of LRLL54361. Balog Z., Muzerolle J., Flaherty K., Detre O.H., Bouwmann J., Furlan E., Gutermuth R., Juhasz A., Bally J., Nielbock M., Klaas U., Krause O., Henning T., Marton G. <Astrophys. J., 789, L38 (2014)> =2014ApJ...789L..38B (SIMBAD/NED BibCode)
ADC_Keywords: Photometry, infrared ; Protostars Keywords: infrared: stars - stars: formation - stars: individual: LRLL54361 - stars: protostars - stars: variables: general Abstract: We report Herschel/Photodetector Array Camera and Spectrometer (PACS) photometric observations at 70 µm and 160 µm of LRLL54361, a suspected binary protostar that exhibits periodic (P = 25.34 days) flux variations at shorter wavelengths (3.6 µm and 4.5 µm) thought to be due to pulsed accretion caused by binary motion. The PACS observations show unprecedented flux variation at these far-infrared wavelengths that are well correlated with the variations at shorter wavelengths. At 70 µm the object increases its flux by a factor of six while at 160 µm the change is about a factor of two, consistent with the wavelength dependence seen in the far-infrared spectra. The source is marginally resolved at 70 µm with varying FWHM. Deconvolved images of the sources show elongations exactly matching the outflow cavities traced by the scattered light observations. The spatial variations are anti-correlated with the flux variation, indicating that a light echo is responsible for the changes in FWHM. The observed far-infrared flux variability indicates that the disk and envelope of this source is periodically heated by the accretion pulses of the central source, and suggests that such long wavelength variability in general may provide a reasonable proxy for accretion variations in protostars. Description: We observed a 14'x14' area in IC348 with the Photodetector Array Camera and Spectrometer (PACS; Poglitsch et al. 2010A&A...518L...2P) Herschel Space Observatory (Pilbratt et al. 2010A&A...518L...1P) simultaneously at 70 and 160um 24 times in scan map mode. An additional five epoch were observed during a later pulse phase of LRLL54361 in all three PACS photometer bands. The PACS spectrograph consists of a 5x5 array of 9.4" x 9.4" spatial pixels (hereafter referred to as spaxels) covering the spectral range from 52-210 um with λ/δλ ∼1000-3000. Spectra were obtained in two spectral orders simultaneously, with the second order ranging from 51 to 105um and the first order from 102 to 210um. The spatial resolution of PACS-S ranges from ∼9'' at 50um to ∼18'' at 210um. Our target was observed in the standard range-scan spectroscopy mode with a grating step size corresponding to Nyquist sampling (see further Poglitsch et al. 2010A&A...518L...2P). Objects: ---------------------------------------------------------- RA (ICRS) DE Designation(s) ---------------------------------------------------------- 03 43 51.02 +32 03 08.1 LRLL54361 = Cl* IC 348 LRL 54361 ---------------------------------------------------------- File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 80 33 Observing log of the observations and measured fluxes
See also: J/A+A/419/999 : Infrared knots along protostellar jets (Giannini+, 2004) J/AJ/144/31 : Spitzer+2MASS photometry of protostar candidates (Kryukova+, 2012) J/AJ/145/94 : Luminosities of protostars from two Spitzer surveys (Dunham+, 2013) J/AJ/151/75 : Herschel-PACS and -SPIRE spectroscopy of 70 objects (Green+, 2016) J/ApJS/224/5 : The Herschel Orion Protostar Survey (HOPS): SEDs (Furlan+, 2016 Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1 I1 --- Cycle ? Cycle number (1) 3- 6 I4 yr Obs.Y Year of the observation 8- 9 I2 "month" Obs.M Month of the observation 11- 12 I2 d Obs.D Day of the observation 14- 15 I2 h Obs.h Hour of the observation 17- 18 I2 min Obs.m Minute of the observation 20- 23 F4.1 s Obs.s Second of the observation 25- 35 F11.3 d JD Julian Date of the observation 37- 41 F5.3 --- Phase Phase (2) 43- 48 F6.3 Jy F70 ? Herschel/PACS 70 micron band flux density 50- 54 F5.3 Jy e_F70 ? Error in F70 56- 61 F6.3 Jy F100 ? Herschel/PACS 100 micron band flux density 63- 67 F5.3 Jy e_F100 ? Error in F100 69- 74 F6.3 Jy F160 ? Herschel/PACS 160 micron band flux density 76- 80 F5.3 Jy e_F160 ? Error in F160
Note (1): The last four lines without Cycle values give the spectrocopy information. The first 29 lines with Cycle values are the photometry. Note (2): We calculated the phase of the observations based on the period of 25.34 days and zero point JD 2455121.203 reported by Muzerolle et al. (2013, J/other/Nat/493.378). Phase=0 corresponds to the peak flux, as measured from the Spitzer/IRAC observations.
History: From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 08-Mar-2017
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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