J/AJ/151/75 Herschel-PACS and -SPIRE spectroscopy of 70 objects (Green+, 2016)
The CDF archive: Herschel PACS and SPIRE spectroscopic data pipeline and
products for protostars and young stellar objects.
Green J.D., Yang Y.-L., Evans II N.J., Karska A., Herczeg G.,
van Dishoeck E.F., Lee J.-E., Larson R.L., Bouwman J.
<Astron. J., 151, 75 (2016)>
=2016AJ....151...75G 2016AJ....151...75G (SIMBAD/NED BibCode)
ADC_Keywords: YSOs ; Spectroscopy ; Line Profiles
Keywords: infrared: stars - stars: formation - submillimeter: ISM -
submillimeter: stars - surveys - techniques: imaging spectroscopy
Abstract:
We present the COPS-DIGIT-FOOSH (CDF) Herschel spectroscopy data
product archive, and related ancillary data products, along with data
fidelity assessments, and a user-created archive in collaboration with
the Herschel-PACS and SPIRE ICC groups. Our products include
datacubes, contour maps, automated line fitting results, and best 1D
spectra products for all protostellar and disk sources observed with
PACS in RangeScan mode for two observing programs: the DIGIT Open Time
Key Program (KPOT_nevans_1 and SDP_nevans_1; PI: N. Evans), and
the FOOSH Open Time Program (OT1_jgreen02_2; PI: J. Green). In
addition, we provide our best SPIRE-FTS spectroscopic products for the
COPS Open Time Program (OT2_jgreen02_6; PI: J. Green) and FOOSH
sources. We include details of data processing, descriptions of output
products, and tests of their reliability for user applications. We
identify the parts of the data set to be used with caution. The
resulting absolute flux calibration has improved in almost all cases.
Compared to previous reductions, the resulting rotational temperatures
and numbers of CO molecules have changed substantially in some
sources. On average, however, the rotational temperatures have not
changed substantially (<2%), but the number of warm (Trot∼300K) CO
molecules has increased by about 18%.
Description:
We present the CDF (COPS-DIGIT-FOOSH) archive, with Herschel
spectroscopic observations of 70 objects (protostars, young stellar
objects, and FU Orionis objects) from the "Dust, Ice, and Gas in Time"
(DIGIT) Key Project, FU Orionis Objects Surveyed with Herschel" Open
Time Program (FOOSH OT1), and "CO in Protostars" Open Time Program
(COPS OT2) Herschel programs. These have been delivered to the
Herschel archive and are available. The full source list is shown in
Table1.
The full DIGIT spectroscopic sample consists of 63 sources: 24 Herbig
Ae/Be stars (intermediate mass sources with circumstellar disks), 9 T
Tauri stars (low mass young stars with circumstellar disks), and 30
protostars (young stars with significant envelope emission) observed
with Photodetector Array Camera and Spectrometer (PACS) spectroscopy.
DIGIT also included an additional wTTS (weak-line T Tauri star) sample
that was observed photometrically and delivered separately. The wTTS
sample is fully described by Cieza et al. 2013ApJ...762..100C 2013ApJ...762..100C. The
full DIGIT embedded protostellar sample consisted of 30 Class 0/I
targets, drawn from previous studies, focusing on protostars with
high-quality Spitzer-IRS 5-40µm spectroscopy (summarized by Lahuis
et al. 2006 c2d Spectroscopy Explanatory Supplement; Pasadena, CA:
Spitzer Science Center), and UV, optical, infrared, and submillimeter
complementary data. These objects are selected from some of the
nearest and best-studied molecular clouds: Taurus (140pc; 6 targets),
Ophiuchus (125pc; 7 targets), Perseus (230-250pc; 7 targets), R Corona
Australis (130pc; 3 targets), Serpens (429pc; 2 targets), Chamaeleon
(178pc, 1 target), and 4 additional isolated cores.
PACS is a 5*5 array of 9.4''*9.4'' spatial pixels (spaxels) covering
the spectral range from 50 to 210µm with
λ/Δλ∼1000-3000, divided into four segments,
covering λ∼50-75, 70-105, 100-145, and 140-210µm. The PACS
spatial resolution ranges from ∼9'' at the shortest wavelengths
(50µm) to ∼18'' at the longest (210µm), corresponding to
1000-4500AU at the distances of most sources. The nominal pointing rms
of the telescope is 2''.
For the DIGIT embedded protostars sample we utilized the full range of
PACS (50-210µm) in two linked, pointed, chop/nod rangescans: a blue
scan covering 50-75 and 100-150µm (SED B2A+short R1); and a red
scan covering 70-105 and 140-210µm (SED B2B+long R1). We used 6 and
4 range repetitions respectively, for integration times of 6853 and
9088s (a total of ∼16000s per target for the entire 50-210µm scan).
Excluding overhead, 50% of the integration time is spent on source and
50% on sky. Thus the effective on-source integration times are 3088
and 4180s, for the blue and red scans, respectively. The total
on-source integration time to achieve the entire 50-210µm scan is
then 7268s. Most (21 of 33) disk sources were observed with the same
procedure as the embedded objects. The other 12 sources have only
partial spectral coverage: 8 Herbig Ae/Be sources (HD35187, HD203024,
HD245906, HD142666, HD144432, HD141569, HD98922, and HD150193) and 4 T
Tauri sources (HT Lup, RU Lup, RY Lup, and RNO90) were observed using
only the blue scans (i.e., achieving a wavelength coverage only from
SED B2A+short R1, 100-150µm). 9 of these 12 sources (all except
HD35187, HD203024, and HD245906) were observed in a further limited
wavelength range (60-72+120-134µm; referred to as "forsterite
only" scans for their focus on the 69µm forsterite dust feature).
The FU Orionis Objects Surveyed with Herschel (FOOSH) program
consisted of 21hrs of Herschel observing time: V1057Cyg, V1331Cyg,
V1515Cyg, V1735Cyg, and FUOri were observed as part of FOOSH. For the
FOOSH sample we again utilized the full range of PACS (50-210µm) in
two linked, pointed, chop/nod rangescans: a blue scan covering 50-75
and 100-150µm (SED B2A+short R1); and a red scan covering 70-105
and 140-210µm (SED B2B+long R1). We used 6 and 4 range repetitions
respectively, for integration times of 3530 and 4620s (a total of
∼8000s per target and off-positions combined, for the entire
50-210µm scan; the on-source integration time is ∼3000s). The
telescope sky background was subtracted using two nod positions 6'
from the source. The Spectral and Photometric Imaging REceiver (SPIRE;
194-670µm)/Fourier Transform Spectrometer (FTS) data were taken in
a single pointing with sparse image sampling, high spectral resolution
mode, over 1hr of integration time. The spectrum is divided into two
orders covering the spectral ranges 194-325µm ("SSW"; Spectrograph
Short Wavelengths) and 320-690µm ("SLW"; Spectrograph Long
Wavelengths), with a resolution, Δv of 1.44GHz and resolving
power, λ/Δλ∼300-800, increasing at shorter
wavelengths.
The sample of 31 COPS (CO in ProtoStars) protostars observed with
SPIRE-FTS includes 25 sources from the DIGIT and 6 from the WISH
(Water in Star-forming regions with Herschel, PI: E. van Dischoek; van
Dishoeck et al. 2011PASP..123..138V 2011PASP..123..138V; see also Nisini et al.
2010A&A...518L.120N 2010A&A...518L.120N; Kristensen et al. 2012A&A...542A...8K 2012A&A...542A...8K; Karska et
al. 2013A&A...552A.141K 2013A&A...552A.141K; Wampfler et al. 2013A&A...552A..56W 2013A&A...552A..56W) key
programs. A nearly identical sample was observed in COJ=16->15 with
HIFI (PI: L. Kristensen) and is presented in L. Kristensen et al.
2016, (in preparation). This data set (COPS: SPIRE-FTS) is analyzed in
a forthcoming paper (J. Green et al. 2016, in preparation). The SPIRE
beamsize ranges from 17'' to 40'', equivalent to physical sizes of
∼2000-10000AU at the distances of the COPS sources.
The COPS SPIRE-FTS data were observed identically to the FOOSH SPIRE
data, in a single pointing with sparse image sampling, high spectral
resolution, in 1hr of integration time per source, with one exception:
the IRS 44/46 data were observed in medium image sampling (e.g.,
complete spatial coverage within the inner 2 rings of spaxels), in
1.5hr, in order to better distinguish IRS44 (the comparatively
brighter IR source; Green et al. 2013ApJ...770..123G 2013ApJ...770..123G, J. Green et al.
2016, in preparation) from IRS46.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 102 74 Archive sources
table8.dat 223 324920 The 1D spectrum fitting results
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See also:
J/ApJS/181/321 : Properties of Spitzer c2d dark clouds (Evans+, 2009)
J/A+A/432/369 : Leiden Atomic and Molecular Database (LAMDA) (Schoeier+, 2005)
http://www.cosmos.esa.int/web/herschel/user-provided-data-products : Herschel
Science Archive (HSA) User Provided Data Products
ftp://hsa.esac.esa.int/LEGACY_PRODUCTS/UPDP/DIGIT/ : DIGIT-FOOSH-COPS files
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- Name Source name
17- 22 A6 --- n_Name Note for IRS44/IRS46 data (1)
24- 38 A15 --- OName Other name
40- 49 I10 --- PObsID1 ? Herschel/Photodetector Array Camera and
Spectrometer (PACS) first ObsID
50 A1 --- --- [,]
51- 60 I10 --- PObsID2 ? Herschel/PACS second ObsID
62- 71 I10 --- SPObsID ? Herschel/Spectral and Photometric Imaging
REceiver (SPIRE) ObsID
73- 74 I2 h RAh Hour of Right Ascension (J2000)
76- 77 I2 min RAm Minute of Right Ascension (J2000)
79- 82 F4.1 s RAs Second of Right Ascension (J2000)
84 A1 --- DE- Sign of the Declination (J2000)
85- 86 I2 deg DEd Degree of Declination (J2000)
88- 89 I2 arcmin DEm Arcminute of Declination (J2000)
91- 94 F4.1 arcsec DEs Arcsecond of Declination (J2000)
96- 98 A3 --- Prog Observing program (C=COPS, D=DIGIT, F=FOOSH) (2)
100 A1 --- Jit [x] Accessibility of the Jitter corrected data
(x=source using the Jitter-corrected products)
102 A1 --- 1D [x] Indicates the accessibility of SPIRE extended
calibrated 1D spectra
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Note (1): In the DIGIT sample, the two sources IRS44 and IRS46 were observed in
a single pointing centered on IRS46. In the COPS data, IRS 44/46 were
observed in medium image sampling (e.g., complete spatial coverage within
the inner 2 rings of spaxels), in 1.5hr, in order to better distinguish
IRS44 (the comparatively brighter IR source; Green et al.
2013ApJ...770..123G 2013ApJ...770..123G, J. Green et al. 2016, in preparation) from IRS46.
Note (2):
The first program in which the source was observed are defined as below
(see the "Description" section above for further details):
C = CO in ProtoStars (COPS) open time program;
D = Dust, Ice, and Gas in Time (DIGIT) open time key program;
F = FU Orionis Objects Surveyed with Herschel (FOOSH) open time program.
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Byte-by-byte Description of file: table8.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- Name Object identifier
17 A1 --- Comp Component B for "HD 135344"
19- 35 A17 --- Line Species and transition of line identifier
37- 45 F9.5 um Llambda [54.9/650.3] Laboratory/theoretical
wavelength (LabWL) (1)
47- 55 F9.5 um Olambda [54.9/652.9] Fitted wavelength (ObsWL)
57- 66 F10.5 um e_Olambda [-999/338.3] Uncertainty in Olambda
(Sig_Cen) (2)
68- 80 E13.6 W/cm2 Str Integrated line strength (Str) (3)
82- 94 A13 W/cm2 e_Str Uncertainty in Str (Sig_str) (2)
96-102 F7.5 um FWHM [0.02/4] Full width at half maximum of the
fitted Gaussian profile
104-113 F10.5 um e_FWHM [-999/54.5] Uncertainty in FHWM (Sig_FWHM) (2)
115-127 E13.6 W/cm2/um Base Specific flux of fitted continuum of the
fitted continuum at the line centroid
129-140 E12.6 W/cm2/um Noise Noise level (4)
142-151 F10.6 --- S/N [0/351.2] Signal-to-Noise ratio of fitted line
strength
153-161 F9.4 K Eup [23/6458] Upper level transition energy (E_u)
163-173 E11.5 s-1 A [0/2.5] Einstein A value of transition
175-176 I2 --- g [1/97] Multiplicity of upper level of
transition
178-188 F11.7 deg RAdeg Right Ascension in decimal degrees
(J2000) (5)
190-200 F11.7 deg DEdeg Declination in decimal degrees (J2000) (5)
202-206 A5 --- Npix The number of spatial pixels (or "spaxels")
(Pixel_No) (6)
208-221 A14 --- Blend Status of blended lines (DoubleGaussian, Red,
Red/Blue, or x) (7)
223 I1 --- V [0/1] Validity suggestion (1=recommended line
identification) (8)
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Note (1): The theoretical information of each transition is acquired from Leiden
Atomic and Molecular Database (LAMDA; Schoier et al. 2005,
Cat. J/A+A/432/369).
Note (2):
The "-999" and "-998" values in e_Olambda and e_FWHM, and the "-999"
values in e_Str are defined as below:
-999 = A fitting result that is not well-constrained and therefore the
Validity flag is set to zero. See Section 4.6.
-998 = The fitted parameters may be used but the uncertainties are not
calculated (but can be reasonably inferred from neighboring line
fits).
Note (3): Calculated from the fitted Gaussian profile. The unit in the table is
flux for both SPIRE and PACS fitting results. A negative Str value with
S/N≥3 may indicate an absorption line, but may be a strong emission line
the off-position.
Note (4): Calculated from the residual of second fitting and the line
subtraction procedure (see Section 4.5).
Note (5): Of the object or spatial pixel (spaxel).
Note (6): Or name of PACS and SPIRE module. In PACS, they are labeled
numerically, while specific names are assigned in SPIRE module. This line
is labeled "c" for the 1D spectra line fitting results and the specific
pixel number/name for cube measurements.
Note (7): Blended lined fitting defined as below (more details in Section 4.4):
x = This line is not blended;
Red = Line blended with another component at longer wavelength;
Blue = Line blended with another component at shorter wavelength;
Red/Blue = Line blended at both side of the line profile;
DoubleGaussian = Double Gaussian function used to fit the blended profile.
Note (8): The overall suggestion whether to use this fitted line profile based
on the fitting quality and blending criteria. Our recommended line
identification is simply the line with the highest Einstein-A coefficient,
as the level population dependence on physical conditions can be
complicated. These blended lines are typically water lines with similar
excitation requirements. These recommendations for line identification are
recorded as "1" in the validity column. More details in Section 4.4.
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History:
From electronic version of the journal
(End) Prepared by [AAS]; Sylvain Guehenneux [CDS] 06-Oct-2016