Variable Ultraviolet Absorption in the Seyfert 1 Galaxy NGC 3516: The Case for Associated Ultraviolet and X‐Ray Absorption

Kraemer, S. B.; Crenshaw, D. Michael; George, I. M.; Netzer, H.; Turner, T. J.; Gabel, J. R.

doi:10.1086/342173

Cited by 58 publications

(110 citation statements)

References 64 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The five major kinematic components of absorption have maintained their presence throughout the ∼eight years of high-resolution UV observations, 10 despite a wide range in continuum flux levels. We find no evidence for the appearance of new components or the disappearance of previous components of intrinsic absorption, which we have seen in the Seyfert 1 galaxies NGC 3783 (Kraemer et al 2001;Gabel et al 2005) and NGC 3516 (Kraemer et al 2002). …”

Section: Observationscontrasting

confidence: 78%

“…There is extensive evidence that the NLR emission in other Seyfert galaxies is not, in general, covered by the intrinsic UV absorbers (Arav et al 2002;Kraemer et al 2002;Gabel et al 2003;). If we assume that the NLR is uncovered and that all of the other emission components are covered by the same fraction, then we can use the traditional doublet method (Hamann et al 1997) to determine the line-ofsight covering factors (C f ) and ionic columns densities of the absorption components.…”

Section: Partial Covering Of All Emission Components Except the Nlrmentioning

confidence: 99%

See 1 more Smart Citation

Mass Outflow in the Seyfert 1 Galaxy NGC 5548

Crenshaw

Kraemer

Schmitt

et al. 2009

ApJ

Self Cite

View full text Add to dashboard Cite

We present a study of the intrinsic UV absorption and emission lines in an historically low-state spectrum of the Seyfert 1 galaxy NGC 5548, which we obtained in 2004 February at high spatial and spectral resolution with the Space Telescope Imaging Spectrograph on the Hubble Space Telescope. We isolate a component of emission with a width of 680 km s −1 that arises from an "intermediate-line region" (ILR), similar to that we discovered in NGC 4151, at a distance of ∼1 pc from the central continuum source. From a detailed analysis of the five intrinsic absorption components in NGC 5548 and their behavior over a span of eight years, we present evidence that most of the UV absorbers only partially cover the ILR and do not cover an extended region of UV continuum emission, most likely from hot stars in the circumnuclear region. We also find that four of the UV absorbers are at much greater distances (greater than 70 pc) than the ILR, and none have sufficient N v or C iv column densities to be the ILR in absorption. At least a portion of the UV absorption component 3, at a radial velocity of −530 km s −1 , is likely responsible for most of the X-ray absorption, at a distance less than 7 pc from the central source. The fact that we see the ILR in absorption in NGC 4151 and not in NGC 5548 suggests that the ILR is located at a relatively large polar angle (∼45 • ) with respect to the narrow-line region outflow axis.

show abstract

Section: Observationscontrasting

confidence: 78%

Section: Partial Covering Of All Emission Components Except the Nlrmentioning

confidence: 99%

Mass Outflow in the Seyfert 1 Galaxy NGC 5548

Crenshaw

Kraemer

Schmitt

et al. 2009

ApJ

Self Cite

View full text Add to dashboard Cite

show abstract

“…To illustrate this, we generated a filtered ionizing continuum by modifying our NLSy1 SED via transmission through an absorber of ionization parameter U = 0.005, and total column density of 2.5 x 10 20 cm −2 . These parameters were chosen to drop the ionization parameter, for the conditions assumed in the higher ionization NLSy1 model, from 0.00215 to 0.001, and are similar to the strong components of intrinsic UV absorption detected in NGC 4151 (Kraemer et al 2001) and NGC 3516 (Kraemer et al 2002). The filtered continnum is shown as the dotted line in Figure 2, and is clearly optically thick just above the H and He II Lyman limits.…”

Section: Luminosity Comparisonmentioning

confidence: 99%

On the Relationship between the Optical Emission‐Line and X‐Ray Luminosities in Seyfert 1 Galaxies

Kraemer

George

Crenshaw

et al. 2004

ApJ

Self Cite

View full text Add to dashboard Cite

We have explored the relationship between the [O III] λ5007 and the 2-10 keV luminosities for a sample of Broad-and Narrow-Line Seyfert 1 galaxies (BLSy1 and NLSy1, respectively). We find that both types of Seyferts span the same range in luminosity and possess similar [O III]/X-ray ratios. The NLSy1s are more luminous than BLSy1s, when normalized to their central black hole masses, which is attributed to higher mass accretion rates. However, we find no evidence for elevated [O III]/X-ray ratios in NLSy1s, which would have been expected if they had excess EUV continuum emission compared to BLSy1s. Also, other studies suggest that the gas in narrow-line regions (NLR) of NLSy1s and NLSy1s span a similar range in ionization, contrary to what is expected if those of the former are exposed to a stronger flux of EUV radiation. The simplest interpretation is that, like BLSy1s, a large EUV bump is not present in NLSy1s. However, we show that the [OIII]/X-ray ratio can be lowered as a result of absorption of the ionizing continuum by gas close to the central source, although there is no evidence that intrinsic line-of-sight absorption is more common among NLSy1s, as would be expected if there were a larger amount of circumnuclear gas. Other possible explanations include: 1) anisotropic emission of the ionizing radiation, 2) higher gas densities in the NLR of NLSy1s, resulting in lower average

show abstract

“…Some authors discussed the possibility that at least a fraction of the UV absorption is produced in the same gas responsible for the X-ray absorption (Mathur et al 1994(Mathur et al , 1995(Mathur et al , 1999Kriss et al 2000;Kraemer et al 2002), but the results were inconclusive and the connection between the two absorbing components seems to be very complex. The most common source of uncertainty came from the lack of correspondence between the column densities of the species detected in both UV and X-rays.…”

Section: Introductionmentioning

confidence: 99%

Multiwavelength campaign on Mrk 509

Ebrero

Kriss

Kaastra

et al. 2011

A&A

View full text Add to dashboard Cite

Context. We present here the results of a 180 ks Chandra-LETGS observation as part of a large multi-wavelength campaign on Mrk 509. Aims. We study the warm absorber in Mrk 509 and use the data from a simultaneous HST-COS observation in order to assess whether the gas responsible for the UV and X-ray absorption are the same. Methods. We analyzed the LETGS X-ray spectrum of Mrk 509 using the SPEX fitting package. Results. We detect several absorption features originating in the ionized absorber of the source, along with resolved emission lines and radiative recombination continua. The absorption features belong to ions with, at least, three distinct ionization degrees. The lowest ionized component is slightly redshifted (Δv = 73 km s −1 ) and is not in pressure equilibrium with the others, and therefore it is not likely part of the outflow, possibly belonging to the interstellar medium of the host galaxy. The other components are outflowing at velocities of −196 and −455 km s −1 , respectively. The source was observed simultaneously with HST-COS, finding 13 UV kinematic components. At least three of them can be kinematically associated with the observed X-ray components. Based on the HST-COS results and a previous FUSE observation, we find evidence that the UV absorbing gas might be co-located with the X-ray absorbing gas and belong to the same structure.

show abstract

Variable Ultraviolet Absorption in the Seyfert 1 Galaxy NGC 3516: The Case for Associated Ultraviolet and X‐Ray Absorption

Cited by 58 publications

References 64 publications

Mass Outflow in the Seyfert 1 Galaxy NGC 5548

Mass Outflow in the Seyfert 1 Galaxy NGC 5548

On the Relationship between the Optical Emission‐Line and X‐Ray Luminosities in Seyfert 1 Galaxies

Multiwavelength campaign on Mrk 509

Contact Info

Product

Resources

About