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Survey of the Low-Redshift Intergalactic Medium with HST/COS

Danforth et al. (2015), accepted, arXiv1402.2655D

Example subsection of a spectrum for the IGM sightline 3C57. Features marked in red are intergalactic absorber lines from systems at various redshifts.

Introduction

A survey of the low-redshift intergalactic medium (IGM) has been performed by Danforth et al. (2015). Using HST COS spectra of 82 UV-bright AGN, several thousand absorption lines are identified from 2,610 distinct redshift systems at z < 0.723. The spectral features were selected and measured using a semi-automated analysis to minimize bias in line identification. For each of the 82 sightlines, a coadded, continuum-fitted spectrum is provided in FITS format (*_spec.fits). Two catalogs for each sightline are presented: one catalog lists the identified spectral features sorted by wavelength (*_linelist.txt files), while another lists the absorption features associated with IGM systems sorted by redshift (*_igm_systems.txt). Finally, preview plots of each sightline's spectrum are provided in PDF and PS format, complete with line identifications (*_atlas.pdf / *_atlas.ps). For convenience, we provide machine-readable versions of Table 1 and Table 2 from Danforth et al. 2015.

Note: this third version (v3) of the catalog replaces the 2014 version with a more accurate data reduction, higher S/N spectra, and a somewhat expanded list of sources. In addition, we include a "Galactic foreground" spectrum useful in identifying commonly-observed absorption features arising in the Galactic ISM. This spectrum is generated by median-combining the entire sample of 82 normalized spectra in observed wavelength. It is very high S/N and reveals the presence of many very weak absorption lines which may occasionally appear in spectra. You can download the Galactic foreground FITS, PS, and PDF files at the top of the target table.

FITS File Spectra - Data Format

The FITS headers and data format of the *_spec.fits files are summarized in this table (show / hide).

Quick-Look Plots - Data Format

An explanation of the quick-look plots' legends and data format (*_atlas.ps and *_atlas.pdf files) are summarized in this section (show / hide).

IGM Atlas, Plot Tool, and Data Download

Links provide access to download the spectrum (FITS file), visit interactive plot for that sightline, view the quick-look preview plots for the spectrum, and download the catalog of linelists or absorber systems for each sightline. To access the interactive plots, click on the "INT" link in the PLOTS column in the table.

Click here to bulk-download a gzipped tarball (110 MB) containing all files for every sight line. Click here for a machine-readable version of this table. Note that the flux column is the median continuum flux in units of 10-15 erg cm-2 s-1 Å-1.

Galactic Foregound Model  SPECTRUM (FITS)  PLOTS: (INT) (PS) (PDF)
Sightline Name Short Name RA (deg)
(J2000)
DEC
(J2000)
AGN z
(Redshift)
Flux AGN Type SPECTRUM LINELIST SYSTEMS PLOTS
1ES1028+511 1es1028 157.8270833 50.893333 0.3604 2.6 BLLac FITS TXT TXT INT PS PDF
1ES1553+113 1es1553 238.9293500 11.190103 0.4140 15.9 BLLac/FSRQ FITS TXT TXT INT PS PDF
1SAXJ1032.3+5051 1sj1032 158.0670833 50.855556 0.1731 1.1 AGN FITS TXT TXT INT PS PDF
3C263 3c263 174.9874458 65.796997 0.6460 10.4 FR2/Sy1.2 FITS TXT TXT INT PS PDF
3C273 3c273 187.2778962 2.052406 0.1583 461.5 FSRQ/Sy1.0 FITS TXT TXT INT PS PDF
3C57 3c57 30.4881667 -11.542536 0.6705 6.6 Sy1.2 FITS TXT TXT INT PS PDF
3C66A 3c66a 35.6650500 43.035500 0.3347 6.8 BLLac FITS TXT TXT INT PS PDF
B0117-2837 b0117 19.8987358 -28.358731 0.3489 11.6 Sy1.0 FITS TXT TXT INT PS PDF
FBQSJ1010+3003 f1010 152.5029167 30.056111 0.2558 2.5 QSO FITS TXT TXT INT PS PDF
H1821+643 h1821 275.4887500 64.343333 0.2968 53.0 Sy1.2 FITS TXT TXT INT PS PDF
H2356-309 h2356 359.7830500 -30.628031 0.1651 1.8 BLLac FITS TXT TXT INT PS PDF
HE0056-3622 he0056 14.6557779 -36.101397 0.1641 17.3 Sy1 FITS TXT TXT INT PS PDF
HE0153-4520 he0153 28.8050000 -45.103333 0.4510 15.8 QSO FITS TXT TXT INT PS PDF
HE0226-4110 he0226 37.0633004 -40.954058 0.4934 21.4 Sy1.0 FITS TXT TXT INT PS PDF
HE0238-1904 he0238 40.1354167 -18.864167 0.6310 14.0 QSO FITS TXT TXT INT PS PDF
HE0435-5304 he0435 69.2116667 -52.980278 0.4300 2.5 QSO FITS TXT TXT INT PS PDF
HS1102+3441 hs1102 166.4158254 34.426222 0.5088 3.6 QSO FITS TXT TXT INT PS PDF
IRASF22456-5125 i22456 342.1716850 -51.164764 0.1000 19.3 Sy1.5 FITS TXT TXT INT PS PDF
IRASL06229-6434 i06229 95.7820000 -64.605750 0.1290 8.0 FSRQ FITS TXT TXT INT PS PDF
MR2251-178 mr2251 343.5245000 -17.582028 0.0640 34.3 Sy1.5 FITS TXT TXT INT PS PDF
MRK106 mrk106 139.9806683 55.360397 0.1230 11.4 Sy1.0 FITS TXT TXT INT PS PDF
MRK1513 mrk1513 323.1163333 10.138528 0.0630 17.5 Sy1.5 FITS TXT TXT INT PS PDF
MRK478 mrk478 220.5311250 35.439722 0.0791 26.4 NLSy1 FITS TXT TXT INT PS PDF
MRK876 mrk876 243.4883333 65.719444 0.1290 39.5 Sy1 FITS TXT TXT INT PS PDF
PG0003+158 pg0003 1.4968167 16.163614 0.4509 7.7 Sy1.2 FITS TXT TXT INT PS PDF
PG0026+129 pg0026 7.3071250 13.267778 0.1420 19.1 Sy1 FITS TXT TXT INT PS PDF
PG0157+001 pg0157 29.9593750 0.394806 0.1631 20.4 Sy1.5 FITS TXT TXT INT PS PDF
PG0804+761 pg0804 122.7441963 76.044894 0.1000 79.6 Sy1.0 FITS TXT TXT INT PS PDF
PG0832+251 pg0832 128.8991667 24.994722 0.3298 3.5 QSO FITS TXT TXT INT PS PDF
PG0838+770 pg0838 131.1885833 76.885972 0.1310 8.5 Sy1.0 FITS TXT TXT INT PS PDF
PG0844+349 pg0844 131.9268750 34.751222 0.0640 25.5 Sy1.0 FITS TXT TXT INT PS PDF
PG0953+414 pg0953 149.2183750 41.256139 0.2341 38.1 QSO FITS TXT TXT INT PS PDF
PG1001+291 pg1001 151.0107771 28.926439 0.3297 10.6 Sy1 FITS TXT TXT INT PS PDF
PG1011-040 pg1011 153.5861667 -4.311244 0.0583 16.2 Sy1.2 FITS TXT TXT INT PS PDF
PG1048+342 pg1048 162.9329000 33.990750 0.1671 5.9 Sy1.0 FITS TXT TXT INT PS PDF
PG1049-005 pg1049 162.9645000 -0.854900 0.3599 9.2 Sy1.5 FITS TXT TXT INT PS PDF
PG1115+407 pg1115 169.6262500 40.431667 0.1546 10.5 Sy1.0 FITS TXT TXT INT PS PDF
PG1116+215 pg1116 169.7858333 21.321667 0.1763 45.7 Sy1.0 FITS TXT TXT INT PS PDF
PG1121+422 pg1121 171.1632667 42.029172 0.2250 7.4 Sy1.0 FITS TXT TXT INT PS PDF
PG1216+069 pg1216 184.8372167 6.644033 0.3313 12.3 NLSy1 FITS TXT TXT INT PS PDF
PG1222+216 pg1222 186.2268675 21.379539 0.4320 17.0 Blazar FITS TXT TXT INT PS PDF
PG1229+204 pg1229 188.0150417 20.158167 0.0630 19.2 Sy1.0 FITS TXT TXT INT PS PDF
PG1259+593 pg1259 195.3037500 59.035278 0.4778 15.3 Sy1.0 FITS TXT TXT INT PS PDF
PG1307+085 pg1307 197.4458750 8.330083 0.1550 25.0 Sy1.2 FITS TXT TXT INT PS PDF
PG1309+355 pg1309 198.0739583 35.255861 0.1829 10.1 QSO FITS TXT TXT INT PS PDF
PG1424+240 pg1424 216.7516325 23.800011 0.6035 15.2 BLLac FITS TXT TXT INT PS PDF
PG1435-067 pg1435 219.5672917 -6.972417 0.1260 16.2 QSO FITS TXT TXT INT PS PDF
PG1626+554 pg1626 246.9838333 55.375419 0.1330 22.8 Sy1.0 FITS TXT TXT INT PS PDF
PG2349-014 pg2349 357.9838333 -1.153639 0.1737 29.8 Sy1.2 FITS TXT TXT INT PS PDF
PHL1811 phl1811 328.7562500 -9.373611 0.1920 56.2 NLSy1 FITS TXT TXT INT PS PDF
PHL2525 phl2525 0.1017646 -12.763267 0.1990 17.7 QSO FITS TXT TXT INT PS PDF
PKS0405-123 pks0405 61.9517954 -12.193517 0.5740 32.1 Sy1.2 FITS TXT TXT INT PS PDF
PKS0552-640 pks0552 88.1020833 -64.036333 0.6800 11.1 AGN FITS TXT TXT INT PS PDF
PKS0558-504 pks0558 89.9474583 -50.447750 0.1372 28.1 NLSy1/FSRQ FITS TXT TXT INT PS PDF
PKS0637-752 pks0637 98.9437500 -75.271336 0.6500 8.0 FSRQ FITS TXT TXT INT PS PDF
PKS1302-102 pks1302 196.3875000 -10.555278 0.2784 14.9 FSRQ/Sy1.2 FITS TXT TXT INT PS PDF
PKS2005-489 pks2005 302.3557942 -48.831589 0.0710 22.3 BLLac FITS TXT TXT INT PS PDF
PKS2155-304 pks2155 329.7169379 -30.225589 0.1165 73.1 BLLac FITS TXT TXT INT PS PDF
PMNJ1103-2329 p1103 165.9066667 -23.491667 0.1860 2.1 BLLac/FSRQ FITS TXT TXT INT PS PDF
PMNJ2345-1555 pmn2345 356.3019263 -15.918842 0.6210 7.0 FSRQ FITS TXT TXT INT PS PDF
Q1230+0115 q1230 187.7083508 1.255972 0.1170 36.3 NLSy1 FITS TXT TXT INT PS PDF
QSO0045+3926 q0045 12.0790833 39.686556 0.1340 9.3 Sy1 FITS TXT TXT INT PS PDF
RBS144 rbs144 15.1130458 -51.231803 0.0628 22.1 Sy1 FITS TXT TXT INT PS PDF
RBS1892 rbs1892 341.3346225 -46.869944 0.2000 20.3 Sy1 FITS TXT TXT INT PS PDF
RBS542 rbs542 66.5029167 -57.200500 0.1040 33.1 Sy1.5 FITS TXT TXT INT PS PDF
RXJ0439.6-5311 rxj0439 69.9110146 -53.192100 0.2430 3.5 Sy1 FITS TXT TXT INT PS PDF
RXJ0503.1-6634 rxj0503 75.7663750 -66.562750 0.0640 6.4 Sy1 FITS TXT TXT INT PS PDF
RXJ2154.1-4414 rxj2154 328.7127688 -44.235000 0.3440 9.8 Sy1 FITS TXT TXT INT PS PDF
RXSJ09565-0452 rxj0956 149.1257500 -4.888056 0.1550 4.6 Sy1 FITS TXT TXT INT PS PDF
S50716+714 s50716 110.4727017 71.343433 0.2315 24.3 BLLac FITS TXT TXT INT PS PDF
SBS1108+560 sbs1108 167.8841667 55.790556 0.7666 4.9 QSO FITS TXT TXT INT PS PDF
SBS1122+594 sbs1122 171.4741250 59.172667 0.8520 2.7 QSO FITS TXT TXT INT PS PDF
SDSSJ080908.13+461925 s080908 122.2839000 46.323800 0.6563 7.2 QSO FITS TXT TXT INT PS PDF
SDSSJ092554.43+453544 s09255b 141.4768500 45.595700 0.3295 5.1 QSO FITS TXT TXT INT PS PDF
SDSSJ092909.79+464424 s092909 142.2907500 46.740000 0.2400 11.5 QSO FITS TXT TXT INT PS PDF
SDSSJ094952.91+390203 s094952 147.4705500 39.034400 0.3656 7.8 QSO FITS TXT TXT INT PS PDF
SDSSJ135712.61+170444 s135712 209.3025000 17.078900 0.1500 4.7 QSO FITS TXT TXT INT PS PDF
TON1187 ton1187 153.2633333 35.856389 0.0789 17.3 Sy1.2 FITS TXT TXT INT PS PDF
TON236 ton236 232.1691746 28.424928 0.4500 6.1 Sy1.2 FITS TXT TXT INT PS PDF
TON580 ton580 172.7895833 31.234722 0.2902 9.5 Sy1.0/FSRQ? FITS TXT TXT INT PS PDF
TONS210 tons210 20.4646250 -28.349389 0.1160 35.9 Sy1.0 FITS TXT TXT INT PS PDF
UKS0242-724 uks0242 40.7900000 -72.280111 0.1018 10.3 Sy1.2 FITS TXT TXT INT PS PDF

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