Atlas of Spectral Features Found in Cataclysmic Variables
D. W. Hoard (Spitzer Science Center, California Institute of Technology)
This web page provides a reference atlas of spectral features that
have been observed in cataclysmic variables to aid in the identification
of features in newly obtained spectra. I will add to the list of sample
spectra whenever I happen to run across a good sample spectrum in the
literature. Figures and captions are from the journal articles cited
in each section.
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Far-ultraviolet (approximately 900–1200 Å):
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DW UMa
(novalike/SW Sex type) – FUSE
915–1185 Å spectrum
from Figure 1 of Hoard et al. 2003, AJ, 126, 2473
(2003AJ....126.2473H)
Total combined FUV spectrum of DW UMa. The
spectrum spans 915–1185 Å the top and bottom panels
overlap the ends of the middle panel by 7.5 Å. Emission
lines are labeled, with widely spaced lines of the same multiplet
indicated by short horizontal bars on the "bookend" transitions,
and multiplets with many closely spaced lines indicated by a
vertical pointer at the midpoint wavelength joined to a horizontal
bar spanning the multiplet transition wavelengths. Airglow lines
(encircled plus signs; identified from Feldman et al. 2001,
J. Geophys. Res., 106, 8119) and ISM lines (ions in italics) are
indicated below the spectrum. The airglow lines have been truncated
at the upper flux limit of the plot. Wavelengths of H I and
He II transitions are shown outside and below the top and
middle panels. Unlabeled hashmarks at the top of each panel are
interstellar molecular hydrogen (H2) transitions.
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Ultraviolet (approximately 1200–3200 Å):
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DW UMa
(novalike/SW Sex type) – HST/STIS and IUE
1150–1700 Å spectrum
from Figure 1 of Knigge et al. 2000, ApJL, 539, L49
(2000ApJ...539L..49K)
Top: DW UMa's out-of-eclipse
UV spectrum in the low state (thick black line). Also shown are
the best-fit synthetic WD spectrum (thin red line) and the
out-of-eclipse UV spectrum in the high state, as observed with
IUE (blue dashed line). The strongest transitions in the
WD-dominated low-state spectrum are indicated.
Bottom: Residuals of the WD model fit to the
low-state spectrum (thin black line); the region shaded in red
encloses +/– 1σ. Suspected interstellar lines
are marked, as are three features that are probably formed in
an outflow from the system. The thick lines on the axis
separating the panels mark the fit windows.
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V884 Her
(AM Her type) – IUE
(a) short (1150–2000 Å)
and (b) long (2200–3200 Å)
wavelength spectra from Figure 1 of Shrader et al. 1997, ApJ, 486, 1006
(1997ApJ...486.1006S)
(a) SWP Spectrum resulting from the
coaddition of four individual SWPs obtained over arbitrary phase
intervals. The vertical axis is flux in
ergs cm-2 s-1 and
the labels indicate our line identifications. (b) LWP Spectrum of
RX J1802.1+1804 [= V884 Her]. Note the unusually strong line of
He II 2733 Å as well as the apparent presence of
He II 2386 Å, 2511 Å. The Bowen
fluorescence lines of O III 3047 Å,
3133 Å are also evident. The latter may be
blended with O III 3123 Å indicating that
multiple branches of the Bowen process are probably occurring.
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Optical (approximately 3200–8000 Å):
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AR UMa
(high field AM Her type) – MMT
echellete spectrum (4300–8700 Å)
from Figure 7 of Schmidt et al. 1999, ApJ, 525, 407
(1999ApJ...525..407S)
(NOTE: an emission line at approximately
4540 Å is identified as He II, but is likely
N III or O III as no He II line exists
near this wavelength.)
Single 300 s MMT echellette exposure showing
the wide range of emission lines available for analysis. Taken at
φ = 0.92, near inferior conjunction of the secondary, line
components due to the free-falling stream and field-dominated flow
are well separated. The inset depicts Hα at a magnification
at which the narrow, high-velocity component (NHVC) is apparent
(see Section 4.3.2). When all 57 exposures are phased, many
additional weak lines are visible. Each panel is the combination
of two spectral orders, except for the bottom panel, which is a
single order.
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V442 Oph
(novalike/SW Sex type) – APO
(4200–5000 Å,5800–6800 Å)
and MMT (4200–7600 Å)
optical spectra from Figure 1 of Hoard, Thorstensen, and Szkody 2000, ApJ, 537, 936
(2000ApJ...537..936H)
Representative spectra of V442 Oph
from each observing run. The flux scale is accurate for the
1999 (MMT) spectrum; the 1995 (APO) and 1998 (APO) spectra have
been normalized to a constant continuum of 1.0 and shifted by
arbitrary amounts for clarity.