J/ApJ/804/7 SaMOSA: optical spectroscopy of 7 Fermi blazars (Isler+, 2015)
The SMARTS Multi-epoch Optical Spectroscopy Atlas (SaMOSA): an analysis
of emission line variability in southern hemisphere Fermi blazars.
Isler J.C., Urry C.M., Bailyn C., Smith P.S., Coppi P., Brady M.,
MacPherson E., Hasan I., Buxton M.
<Astrophys. J., 804, 7 (2015)>
=2015ApJ...804....7I 2015ApJ...804....7I
ADC_Keywords: Photometry, UBVRI ; Spectroscopy ; QSOs
Keywords: BL Lacertae objects: individual: (PKS 0454-234, 3C 454.3,
PKS 1510-089);
galaxies: active; quasars: emission lines; techniques: spectroscopic
Abstract:
We present multi-epoch optical spectroscopy of seven southern
Fermi-monitored blazars from 2008 to 2013 using the Small and Medium
Aperture Research Telescope System (SMARTS), with supplemental
spectroscopy and polarization data from the Steward Observatory. We
find that the emission lines are much less variable than the
continuum; four of seven blazars had no detectable emission line
variability over the 5 yr observation period. This is consistent with
photoionization primarily by an accretion disk, allowing us to use the
lines as a probe of disk activity. Comparing optical emission line
flux with Fermi γ-ray flux and optical polarized flux, we
investigate whether relativistic jet variability is related to the
accretion flow. In general, we see no such dependence, suggesting that
the jet variability is likely caused by internal processes like
turbulence or shock acceleration rather than a variable accretion
rate. However, three sources showed statistically significant emission
line flares in close temporal proximity to very large Fermi
γ-ray flares. While we do not have sufficient emission line data
to quantitatively assess their correlation with the γ-ray flux,
it appears that in some cases the jet might provide additional
photoionizing flux to the broad-line region (BLR), which implies that
some γ-rays are produced within the BLR, at least for these
large flares.
Description:
The SMARTS Multi-epoch Optical Spectroscopy Atlas (SaMOSA) was based
on the original Fermi-LAT "bright source list" released just before
launch in 2008, including those blazars with declination <20°,
given the location of the SMARTS telescopes. Since the purpose of the
current study is to understand broad-line variability, we only include
objects for which at least five epochs of spectroscopy are available,
for a total of seven flat-spectrum Radio Quasars (FSRQs).
The SMARTS Optical/Near-infrared (OIR) photometry is obtained nightly
with the 1.3m + ANDICAM, with spectral coverage from 0.4 to 2.2um.
SMARTS optical spectroscopy was obtained with the 1.5m + Cassegrain
spectrograph (RCSpec).
Since the launch of Fermi, the Steward Observatory of the University
of Arizona has carried out regular, publicly available optical
spectrophotometry and linear spectropolarimetry of a large sample of
γ-ray-bright blazars using the Bok 2.3m and Kuiper 1.54m
telescopes. The SPOL spectropolarimeter is used for this monitoring
program (R∼15-20Å).
Fermi/LAT data were obtained from the first SMARTS photometric
observation for each source through 2013 July 01 (MJD 56474), via the
Fermi Science Support Center website.
We first presented the emission line light curve for 3C 454.3 in Isler
et al. (2013ApJ...779..100I 2013ApJ...779..100I); one can also be seen in
Leon-Tavares et al. (2013, J/ApJ/763/L36) for this epoch.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 69 7 SMARTS Multi-epoch Optical Spectroscopy Atlas
(SaMOSA) blazars and lines identifications
table2.dat 150 218 SaMOSA optical photometry and spectroscopy log
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See also:
J/A+A/562/A79 : Variability of 7 blazars in six bands (Sandrinelli+, 2014)
J/MNRAS/441/1899 : Fermi bright blazars (Fuhrmann+, 2014)
J/MNRAS/439/690 : Optical/γ-ray variability in blazars (Hovatta+, 2014)
J/MNRAS/438/3058 : 15GHz variability of γ-ray blazars (Richards+, 2014)
J/ApJ/763/L36 : MgII & FeII flux of blazar 3C 454.3 (Leon-Tavares+, 2013)
J/ApJS/199/31 : Fermi LAT second source catalog (2FGL) (Nolan+, 2012)
J/ApJS/188/405 : Fermi-LAT first source catalog (1FGL) (Abdo+, 2010)
J/ApJ/722/520 : Gamma-ray light curves of Fermi blazars (Abdo+, 2010)
J/ApJ/700/597 : FERMI LAT detected blazars (Abdo+, 2009)
http://fermi.gsfc.nasa.gov/ssc/data/access/ : Fermi Science Support Center
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- ID Source identifier
14- 17 A4 --- --- [2FGL]
19- 30 A12 --- 2FGL 2FGL identifier
32- 36 F5.3 --- z [0.3/1.5] Redshift
38- 42 A5 --- W1 [Mg II] W1 line identification ("MgII")
45- 52 A8 --- W2 W2 line identification ("C III]", "Hγ"
or "Si III]")
54- 60 A7 --- W3 W3 line identification ("C IV" or "Hβ")
62- 69 A8 --- W4 W4 line identification ("Hα")
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- ID Source identifier
14- 23 A10 "YYYY/MM/DD" Date UT date of the observation
25 A1 --- Obs [t] Observational flag (1)
27- 35 F9.3 d MJD Modified Julian Date of observation
37- 42 F6.3 mag Bmag [15.6/18.9]? B band magnitude (on Landoolt)
44- 48 F5.3 mag e_Bmag [0.004/0.3]? Uncertainty in Bmag
50- 55 F6.3 mag Vmag [15.1/18.5]? V band magnitude (on Landoolt)
57- 61 F5.3 mag e_Vmag [0.004/0.3]? Uncertainty in Vmag
63- 68 F6.3 mag Rmag [14.6/18]? R band magnitude (on Landoolt)
70- 74 F5.3 mag e_Rmag [0.004/0.2]? Uncertainty in Rmag
76- 81 F6.3 mag Jmag [13/16.6]? J band magnitude (on 2MASS)
84- 88 F5.3 mag e_Jmag [0.006/0.2]? Uncertainty in Jmag
90- 95 F6.3 0.1nm W1 [0.1/49]? First emission line width (MgII) (2)
97-103 F7.3 0.1nm e_W1 [0.1/742]? Uncertainty in W1
105-111 F7.3 0.1nm W2 [0.1/602]? Second emission line width (2)
113-121 F9.3 0.1nm e_W2 [0.2/13471]? Uncertainty in W2
123-128 F6.3 0.1nm W3 [0.4/48]? Third emission line width (2)
130-135 F6.3 0.1nm e_W3 [0.2/21]? Uncertainty in W3
137-143 F7.3 0.1nm W4 [11/111]? Fourth emission line width
(Hα) (2)
145-150 F6.3 0.1nm e_W4 [0.6/24]? Uncertainty in W4
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Note (1): The "t" flag, when present, indicates that the equivalent widths are
obtained from Steward Observatory, in all other cases equivalent
widths are from SMARTS.
Note (2): The lines are identified in Table 1, and the widths are given in
Angstrom (Å). Note that the Hα emission in PKS 1510-089
may have second order contamination.
See text for details.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 04-Aug-2015