RECORD
Probing the Balance of AGN and Star-Forming Activity in the Local Universe with ChaMP
Cosmology and Nongalactic Astrophysics · Submitted 22 Sep 2009
abstract compiled · 2026-09-23 · no language-model review
The authors' main claim Interestingly, this is identical to what stellar mass X-ray binaries exhibit, indicating that we have probably found the first empirical evidence for an intrinsic switch in the accretion mode, from advection-dominated flows to standard (disk/corona) accretion modes in supermassive black hole accretors, similar to what has been seen and proposed to happen in stellar mass black hole systems.
The compiled record
The paper's own sentences, arranged. Each label is drawn from a closed vocabulary; the number beside it is the probability the classifier gave that label. Numbers in the tables are the authors', checked by code. No sentence in this record was written by a model.
Open the compiled record
The abstract, sentence by sentence
The combination of the SDSS and the Chandra Multiwavelength Project (ChaMP) currently offers the largest and most homogeneously selected sample of nearby galaxies for investigating the relation between X-ray nuclear emission, nebular line-emission, black hole masses, and properties of the associated stellar populations. We present here novel constraints that both X-ray luminosity Lx and X-ray spectral energy distribution bring to the galaxy evolutionary sequence H II -> Seyfert/Transition Object -> LINER -> Passive suggested by optical data. In particular, we show that both Lx and Gamma, the slope of the power-law that best fits the 0.5 - 8 keV spectra, are consistent with a clear decline in the accretion power along the sequence, corresponding to a softening of their spectra. This implies that, at z ~ 0, or at low luminosity AGN levels, there is an anti-correlation between Gamma and L/Ledd, opposite to the trend exhibited by high z AGN (quasars). The turning point in the Gamma -L/Ledd LLAGN + quasars relation occurs near Gamma ~ 1.5 and L/Ledd ~ 0.01. Interestingly, this is identical to what stellar mass X-ray binaries exhibit, indicating that we have probably found the first empirical evidence for an intrinsic switch in the accretion mode, from advection-dominated flows to standard (disk/corona) accretion modes in supermassive black hole accretors, similar to what has been seen and proposed to happen in stellar mass black hole systems. The anti-correlation we find between Gamma and L/Ledd may instead indicate that stronger accretion correlates with greater absorption. Therefore the trend for softer spectra toward more luminous, high redshift, and strongly accreting AGN/quasars could simply be the result of strong selection biases reflected in the dearth of type 2 quasar detections.
background contribution method result interpretation main claim
| # | sentence | role | the authors' own work | states the main conclusion | strength |
|---|---|---|---|---|---|
| s0 | The combination of the SDSS and the Chandra Multiwavelength Project (ChaMP) currently offers the largest and most homogeneously selected sample of nearby galaxies for investigating the relation between X-ray nuclear emission, nebular line-emission, black hole masses, and properties of the associated stellar populations. | background 0.62 | 0.13 | 0.03 | asserted 1.00 |
| s1 | We present here novel constraints that both X-ray luminosity Lx and X-ray spectral energy distribution bring to the galaxy evolutionary sequence H II -> Seyfert/Transition Object -> LINER -> Passive suggested by optical data. | contribution 0.94 | 0.85 | 0.14 | asserted 0.98 |
| s2 | In particular, we show that both Lx and Gamma, the slope of the power-law that best fits the 0.5 - 8 keV spectra, are consistent with a clear decline in the accretion power along the sequence, corresponding to a softening of their spectra. | result 1.00 | 0.92 | 0.20 | asserted 0.68 |
| s3 | This implies that, at z ~ 0, or at low luminosity AGN levels, there is an anti-correlation between Gamma and L/Ledd, opposite to the trend exhibited by high z AGN (quasars). | interpretation 0.76 | 0.78 | 0.30 | asserted 0.92 |
| s4 | The turning point in the Gamma -L/Ledd LLAGN + quasars relation occurs near Gamma ~ 1.5 and L/Ledd ~ 0.01. | result 1.00 | 0.83 | 0.12 | asserted 1.00 |
| s5 | Interestingly, this is identical to what stellar mass X-ray binaries exhibit, indicating that we have probably found the first empirical evidence for an intrinsic switch in the accretion mode, from advection-dominated flows to standard (disk/corona) accretion modes in supermassive black hole accretors, similar to what has been seen and proposed to happen in stellar mass black hole systems. | interpretation 1.00 | 0.79 | 0.52 | hedged possibility 0.94 |
| s6 | The anti-correlation we find between Gamma and L/Ledd may instead indicate that stronger accretion correlates with greater absorption. | interpretation 0.98 | 0.64 | 0.08 | hedged possibility 1.00 |
| s7 | Therefore the trend for softer spectra toward more luminous, high redshift, and strongly accreting AGN/quasars could simply be the result of strong selection biases reflected in the dearth of type 2 quasar detections. | interpretation 0.80 | 0.13 | 0.09 | hedged possibility 0.99 |
What was examined, and what was not
- arXiv listing abstract v1
- full text
- figures and tables
- references and citing sentences
- relations to other papers
- P abstract
- S sections
- T body sentences
- C citations
- R cross-paper relations
The paper
Original abstract
The combination of the SDSS and the Chandra Multiwavelength Project (ChaMP) currently offers the largest and most homogeneously selected sample of nearby galaxies for investigating the relation between X-ray nuclear emission, nebular line-emission, black hole masses, and properties of the associated stellar populations. We present here novel constraints that both X-ray luminosity Lx and X-ray spectral energy distribution bring to the galaxy evolutionary sequence H II -> Seyfert/Transition Object -> LINER -> Passive suggested by optical data. In particular, we show that both Lx and Gamma, the slope of the power-law that best fits the 0.5 - 8 keV spectra, are consistent with a clear decline in the accretion power along the sequence, corresponding to a softening of their spectra. This implies that, at z ~ 0, or at low luminosity AGN levels, there is an anti-correlation between Gamma and L/Ledd, opposite to the trend exhibited by high z AGN (quasars). The turning point in the Gamma -L/Ledd LLAGN + quasars relation occurs near Gamma ~ 1.5 and L/Ledd ~ 0.01. Interestingly, this is identical to what stellar mass X-ray binaries exhibit, indicating that we have probably found the first empirical evidence for an intrinsic switch in the accretion mode, from advection-dominated flows to standard (disk/corona) accretion modes in supermassive black hole accretors, similar to what has been seen and proposed to happen in stellar mass black hole systems. The anti-correlation we find between Gamma and L/Ledd may instead indicate that stronger accretion correlates with greater absorption. Therefore the trend for softer spectra toward more luminous, high redshift, and strongly accreting AGN/quasars could simply be the result of strong selection biases reflected in the dearth of type 2 quasar detections.
Human review
References
How the literature uses it
3 arXiv papers cite this in 5 sentences
Papers citing it · 4 sentences without a confident label
Uses its data or values 1 paper
-
We include a subset ($N=39$) of X-ray-detected galaxies from [ref] , for which all relevant emission lines are measured with high S/N ($≥3$), using classifications and line ratios from the OSSY catalog[<https://data.kasi.re.kr/vo/OSSY/>] [ref] .
Hector Galaxy Survey: Optical IFU and Chandra Reveal a Low-Luminosity AGN Behind Extended LINER Emission · Comparison samples and broader implications · 0.84
What it cites · 2 sentences without a confident label
Uses the method or tool of 1 paper
-
We present in Figure [ref] a comparison of the degree to which optically and X-ray selected galaxies follow the proposed sequence in terms of the black hole mass $M_BH$, obtained via $σ_*$ measurements and the $M_BH -σ_*$ relation [ref] , the (dust corrected) stellar mass $M^*$ [ref] , the Balmer decrement H$α$/H$β$ as a proxy for dust extinction, the H$δ_A$ Balmer absorption index as a measure of the age of the associated stellar population, $L[O III]$, and the accretion rate expressed as $L/L_edd$, where $L = L_bol = 600 ×L[O III]$ for the bolometric correction [ref] , and the $L[O III]$ is extinction-corrected using the corresponding Balmer decrements and a $τ∝λ^-0.7$ attenuation law [ref] .
Feast and Famine: Regulation of Black Hole Growth in Low Redshift Galaxies · Probing The Sequence · 0.88
Discussion
Know something about this paper? Leave a comment, or highlight any passage above to comment on it.