arXiv subjects

I. E. López

Publications and source records attributed to I. E. López.

9 recordsLinked to original sources

arXiv2025

J-PAS: A value-added catalogue of optical line intensities for nebular emission galaxies (JOLINES)

We present the value-added catalogue JOLINES (J-PAS optical line intensities for nebular emission galaxies), which provides emission-line fluxes in galaxies at from the spectrophotometric catalogues of miniJPAS, J-NEP and the J-PAS early data release (EDR). This catalogue will be updated with future data releases, offering a growing resource for the study of emission-line galaxies. To obtain reliable emission-line fluxes from narrow-band photometry, we employed spectral energy distribution (SED) fitting using CIGALE, a robust tool that reconstructs the continuum emission and ensures accurate flux measurements. This method effectively mitigates uncertainties associated with direct continuum subtraction techniques, and systematics such as absorption components in the emission lines. We validate our approach using simulated observations of galaxy spectra with added noise, testing the method's performance across different equivalent width (EW) regimes and emission-line strengths. Additionally, we compare the recovered emission-line fluxes with spectroscopic measurements from the Sloan Digital Sky Survey (SDSS) and the Dark Energy Spectroscopic Instrument (DESI). Our results show a tight correlation between photometric and spectroscopic fluxes, particularly for bright emission lines, with a typical dispersion of $\sim$0.3 dex. Reliable fluxes are obtained for emission lines with EW $\gtrsim20\, \rm{\mathring{A}}$, in agreement with previous empirical studies. The current catalogue comprises approximately 13,900 sources with reliable flux measurements in the H$α$+[NII] complex and 7,200 in [OIII]$λ5007$, ensuring statistically robust samples for the brightest optical emission lines. This resource will be expanded in future J-PAS releases, facilitating large-scale studies of star formation, AGN activity, and galaxy evolution.

astro-ph.GA↗

arXiv2025

Shocked, Heated, and Now Resolved: H$_2$ excitation in the low-luminosity AGN at M58 core with JWST

We present JWST NIRSpec and MIRI MRS observations of the central kiloparsec of M58 (NGC 4579), a nearby LINER galaxy hosting a low-luminosity AGN (LLAGN; $L_\mathrm{bol} \sim 10^{42}$ erg s$^{-1}$) with a low-power jet. These data provide an unprecedented view of the warm molecular gas phase and reveal clear signatures of feedback. We detect 44 H$_2$ lines, including bright pure rotational lines (S(1)-S(18)) and rovibrational lines up to $ν=2$, probing a wide range of excitation conditions. Excitation diagrams show that rotational lines follow a power-law temperature distribution with an exponential cutoff, consistent with heating by low-velocity shocks. H$_2$ rovibrational lines deviate from thermal models primarily because of sub-thermal excitation at low density. Additionally, there may be a 10% contribution powered by AGN X-ray photons in the nucleus. The dust lanes associated with the spiral inflow appear dynamically undisturbed but show signs of shock heating, while the inner $\sim$200 pc exhibits turbulent kinematics produced by outflowing molecular gas. These results reveal the subtle yet measurable impact of LLAGN feedback on the interstellar medium, demonstrating that even weak, vertically oriented jets and low radiative accretion rates can perturb molecular gas and regulate nuclear reservoirs. This study highlights JWST's transformative ability to uncover hidden modes of AGN feedback.

astro-ph.GA↗

arXiv2024

A Cigale module tailored (not only) for Low-Luminosity AGN

The spectral energy distribution (SED) of low-luminosity active galactic nuclei (LLAGN) presents challenges due to their faint emissions and the complexity of their accretion processes. This study introduces a new CIGALE module tailored for LLAGN, combining the empirical $L_X$-$L_{12μm}$ relationship with physical models like advection-dominated accretion flows (ADAFs) and truncated accretion disks. This module yields a refined depiction of LLAGN emissions, and a mock analysis shows reliable parameter recovery, with only minor biases. We tested the module on a sample of 50 X-ray-detected local galaxies, including LINERs and Seyferts, where it demonstrated good estimation of bolometric luminosities, even in the presence of significant galaxy contamination. Notably, the previous X-ray module failed to provide AGN solutions for this sample, stressing the need for a novel approach. Comparisons with mid-luminosity AGN confirm the module's robustness and applicability to AGN up to $L_X$ < $10^{45}$ erg/s. We also expanded the X-ray to bolometric correction formula, making it applicable to AGN spanning ten orders of magnitude in luminosity, and revealing lower $k_X$ values than typically assumed. Additionally, our analysis of the $α_{ox}$ index, representing the slope between UV and X-ray emissions, uncovered trends that differ from those observed in high-luminosity AGN, suggesting a shift in accretion physics and photon production mechanisms in low-luminosity regimes. These results underscore the importance of a multiwavelength approach in AGN studies and reveal distinct behaviors in LLAGN compared to quasars. Our findings significantly advance the understanding of LLAGN and offer a comprehensive framework for future research aimed at completing the census of the AGN population.

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arXiv2024

A Multi-Wavelength Characterization of the Obscuring Medium at the Center of NGC 6300

Most of the super-massive black holes in the Universe accrete material in an obscured phase. While it is commonly accepted that the "dusty torus" is responsible for the nuclear obscuration, its geometrical, physical, and chemical properties are far from being properly understood. In this paper, we take advantage of the multiple X-ray observations taken between 2007 and 2020, as well as of optical to far infra-red (FIR) observations of NGC 6300, a nearby ($z=0.0037$) Seyfert 2 galaxy. The goal of this project is to study the nuclear emission and the properties of the obscuring medium, through a multi-wavelength study conducted from X-ray to IR. We perform a simultaneous X-ray spectral fitting and optical-FIR spectral energy distribution (SED) fitting to investigate the obscuring torus. For the X-ray spectral fitting, physically motivated torus models, such as borus02, UXClumpy and XClumpy are used. The SED fitting is done using XCIGALE. Through joint analysis, we constrain the physical parameters of the torus and the emission properties of the accreting supermassive black hole. Through X-ray observations taken in the last 13 years, we have not found any significant line-of-sight column density variability for this source, but observed the X-ray flux dropping $\sim40-50\%$ in 2020 with respect to previous observations. The UXClumpy model predicts the presence of an inner ring of Compton-thick gaseous medium, responsible for the reflection dominated spectra above 10 keV. Through multi-wavelength SED fitting, we measure an Eddington accretion rate $λ_{\rm{Edd}}\sim2\times10^{-3}$, which falls in the range of the radiatively inefficient accretion solutions.

astro-ph.HE↗

arXiv2024

MAMBO -- An empirical galaxy and AGN mock catalogue for the exploitation of future surveys

Aims. We present MAMBO, a flexible and efficient workflow to build empirical galaxy and Active Galactic Nuclei (AGN) mock catalogues that reproduce the physical and observational properties of these sources. Methods. We start from simulated dark matter (DM) haloes, to preserve the link with the cosmic web, and we populate them with galaxies and AGN using abundance matching techniques. We follow an empirical methodology, using stellar mass functions (SMF), host galaxy AGN mass functions and AGN accretion rate distribution functions studied at different redshifts to assign, among other properties, stellar masses, the fraction of quenched galaxies, or the AGN activity (demography, obscuration, multiwavelength emission, etc.). Results. As a proof test, we apply the method to a Millennium DM lightcone of 3.14 $\rm deg^2$ up to redshift $z=10$ and down to stellar masses $\mathcal{M} \gtrsim 10^{7.5} \, M_\odot$. We show that the AGN population from the mock lightcone here presented reproduces with good accuracy various observables, such as state-of-the-art luminosity functions in the X-ray up to $z \sim 7$ and in the ultraviolet up to $z \sim 5$, optical/NIR colour-colour diagrams, and narrow emission line diagnostic diagrams. Finally, we demonstrate how this catalogue can be used to make useful predictions for large surveys. Using \textit{Euclid} as a case example, we compute, among other forecasts, the expected surface densities of galaxies and AGN detectable in the \textit{Euclid} $H_{\rm E}$ band. We find that \textit{Euclid} might observe (on $H_{\rm E}$ only) about $10^{7}$ and $8 \times 10^{7}$ Type 1 and 2 AGN respectively, and $2 \times 10^{9}$ galaxies at the end of its 14 679 $\rm deg^2$ Wide survey, in good agreement with other published forecasts.

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arXiv2023

Multi-phase characterization of AGN winds in 5 local type-2 quasars

We present MEGARA (Multi-Espectrógrafo en GTC de Alta Resolución para Astronomía) Integral Field Unit (IFU) observations of 5 local type-2 quasars (QSO2s, z $\sim 0.1$) from the Quasar Feedback (QSOFEED) sample. These active galactic nuclei (AGN) have bolometric luminosities of 10$^{45.5-46}$ erg/s and stellar masses of $\sim$10$^{11}$ M$_{\odot}$. We explore the kinematics of the ionized gas through the [O~III]$λ$5007 $Å$ emission line. The nuclear spectra of the 5 QSO2s, extracted in a circular aperture of $\sim$ 1.2" ($\sim$ 2.2 kpc) in diameter, show signatures of high velocity winds in the form of broad (full width at half maximum; 1300$\leq$FWHM$\leq$2240 km/s and blueshifted components. We find that 4 out of the 5 QSO2s present outflows that we can resolve with our seeing-limited data, and they have radii ranging from 3.1 to 12.6 kpc. In the case of the two QSO2s with extended radio emission, we find that it is well-aligned with the outflows, suggesting that low-power jets might be compressing and accelerating the ionized gas in these radio-quiet QSO2s. In the four QSO2s with spatially resolved outflows, we measure ionized mass outflow rates of 3.3-6.5 Msun/yr when we use [S~II]-based densities, and of 0.7-1.6 Msun/yr when trans-auroral line-based densities are considered instead. We compare them with the corresponding molecular mass outflow rates (8 - 16 Msun/yr), derived from CO(2-1) ALMA observations at 0.2" resolution. Both phases show lower outflow mass rates than those expected from observational scaling relations where uniform assumptions on the outflow properties were adopted. This might be indicating that the AGN luminosity is not the only driver of massive outflows and/or that these relations need to be re-scaled using accurate outflow properties. We do not find a significant impact of the outflows on the global star formation rates.

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arXiv2023

The miniJPAS survey: AGN & host galaxy co-evolution of X-ray selected sources

Studies indicate strong evidence of a scaling relation in the local Universe between the supermassive black hole mass ($M_\rm{BH}$) and the stellar mass of their host galaxies ($M_\star$). They even show similar histories across cosmic times of their differential terms: star formation rate (SFR) and black hole accretion rate (BHAR). However, a clear picture of this coevolution is far from being understood. We select an X-ray sample of active galactic nuclei (AGN) up to $z=2.5$ in the miniJPAS footprint. Their X-ray to infrared spectral energy distributions (SEDs) have been modeled with CIGALE, constraining the emission to 68 bands. For a final sample of 308 galaxies, we derive their physical properties (e.g., $M_\star$, $\rm{SFR}$, $\rm{SFH}$, and $L_\rm{AGN}$). We also fit their optical spectra for a subsample of 113 sources to estimate the $M_\rm{BH}$. We calculate the BHAR depending on two radiative efficiency regimes. We find that the Eddington ratios ($λ$) and its popular proxy ($L_\rm{X}$/$M_\star$) have 0.6 dex of difference, and a KS-test indicates that they come from different distributions. Our sources exhibit a considerable scatter on the $M_\rm{BH}$-$M_\star$ relation, which can explain the difference between $λ$ and its proxy. We also model three evolution scenarios to recover the integral properties at $z=0$. Using the SFR and BHAR, we show a notable diminution in the scattering between $M_\rm{BH}$-$M_\star$. For the last scenario, we consider the SFH and a simple energy budget for the AGN accretion, obtaining a relation similar to the local Universe. Our study covers $\sim 1$ deg$^2$ in the sky and is sensitive to biases in luminosity. Nevertheless, we show that, for bright sources, the link between SFR and BHAR, and their decoupling based on an energy limit is the key that leads to the local $M_\rm{BH}$-$M_\star$ scaling relation.

astro-ph.GA↗

arXiv2022

Disentangling the nature of the prototype radio weak BL Lac: Contemporaneous multifrequency observations of WISE J141046.00 + 740511.2

Context. The gamma-ray emitting source WISE J141046.00+740511.2 has been associated with a Fermi-LAT detection by crossmatching with Swift/XRT data. It has shown all the canonical observational characteristics of a BL Lac source, including a power-law, featureless optical spectrum. However, it was only recently detected at radio frequencies and its radio flux is significantly low. Aims. Given that a radio detection is fundamental to associate lower-energy counterparts to Fermi-LAT sources, we aim to unambiguously classify this source by performing a multiwavelength analysis based on contemporaneous data. Methods. By using multifrequency observations at the Jansky Very Large Array, Giant Metrewave Radio Telescope, Gran Telescopio Canarias, Gemini, William Herschel Telescope and Liverpool observatories, together with Fermi-LAT and Swift data, we carried out two kinds of analyses. On one hand, we studied several known parameters that account for the radio loudness or weakness characterization and their application to blazars (in general) and to our source (in particular). And, on the other hand, we built and analyzed the observed spectral energy distribution (SED) of this source to try to explain its peculiar characteristics. Results. The multiwavelength analysis indicates that WISE J141046.00+740511.2 is a blazar of the high-frequency peaked (HBL) type that emits highly polarized light and that is likely located at a low redshift. In addition, the one-zone model parameters that best fit its SED are those of an extreme HBL (EHBL); this blazar type has been extensively predicted in theory to be lacking in the radio emission that is otherwise typical of canonical gamma-ray blazars. Conclusions. We confirm that WISE J141046.00+740511.2 is indeed a highly polarized BL Lac of the HBL type. Further studies will be conducted to explain the atypical low radio flux detected for this source.

astro-ph.HE↗

arXiv2020

On the origin of X-ray oxygen emission-lines in obscured AGN

We present the Catalog of High REsolution Spectra of Obscured Sources (CHRESOS) from the XMM-Newton Science Archive. It comprises the emission-line luminosities of H- and He-like transitions from C to Si, and the Fe 3C and Fe 3G L-shell ones. Here, we concentrate on the soft X-ray OVII(f) and OVIII Ly_alpha emission lines to shed light onto the physical processes with which their formation can be related to: active galactic nucleus vs. star forming regions. We compare their luminosity with that of two other important oxygen key lines [OIII]5007A, in the optical, and [OIV]25.89mic, in the IR. We also test OVII(f) and OVIIILy_alpha luminosities against that of continuum bands in the IR and hard X-rays, which point to different ionization processes. We probe into those processes by analyzing photoionization and colisional ionization model predictions upon our lines. We show that both scenarios can explain the formation and observed intensities of OVII(f) and OVIII Ly_alpha. By analyzing the relationships between OVII(f) and OVIII Ly_alpha, and all other observables: [OIII]5007A, [OIV]25.89mic emission lines, and MIR-12mic, FIR-60mic, FIR-100mic, 2-10 keV and 14-195 keV continuum bands, we conclude that the AGN radiation field is mainly responsible of the soft X-ray oxygen excitation.

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