Multi-phase outflows in Mkn 848 observed with SDSS-MaNGA Integral Field Spectroscopy

The characterisation of galaxy-scale outflows in terms of their multi-phase nature, amount, and effects of flowing material is crucial to place constraints on models of galaxy evolution. This study can proceed only with the detailed investigation of individual targets. We present a spatially resolved spectroscopic optical data analysis of Mkn 848, a complex system consisting of two merging galaxies at z~0.04 that are separated 7.5 kpc (projected distance). Motivated by the presence of a multi-phase outflow in the north-west system revealed by the SDSS integrated spectrum, we analysed the publicly available MaNGA data, which cover almost the entire merging system, to study the physical properties of cool and warm gas in detail. Galaxy-wide outflowing gas in multiple phases is revealed for the first time in the two merging galaxies. We also detect spatially resolved resonant NaID emission associated with the outflows. The derived outflow energetics may be consistent with a scenario in which both winds are accelerated by stellar processes and AGN activity, although we favour an AGN origin given the high outflow velocities and the ionisation conditions observed in the outflow regions. Deeper observations are required, however, to better constrain the nature of these multi-phase outflows. Outflow energetics in the north-west system are strongly different between the ionised and atomic gas components, the latter of which is associated with mass outflow rate and kinetic and momentum powers that are 1-2 dex higher; those associated with the south-east galaxy are instead similar. Strong kp-scale outflows are revealed in an ongoing merger system, suggesting that feedback can potentially impact the host galaxy even in the early merger phases. The characterisation of the neutral and ionised gas phases has proved to be crucial for a comprehensive study of the outflow phenomena.Comment: 19 pages, 14 figures, accepted for publication in A&

X-ray redshifts for obscured AGN: a case study in the J1030 deep field

We present a procedure to constrain the redshifts of obscured ($N_H > 10^{22}$ cm$^{-2}$) Active Galactic Nuclei (AGN) based on low-count statistics X-ray spectra, which can be adopted when photometric and/or spectroscopic redshifts are unavailable or difficult to obtain. We selected a sample of 54 obscured AGN candidates on the basis of their X-ray hardness ratio, $HR>-0.1$, in the Chandra deep field ($\sim$479 ks, 335 arcmin$^2$) around the $z=6.3$ QSO SDSS J1030+0524. The sample has a median value of $\approx80$ net counts in the 0.5-7 keV energy band. We estimate reliable X-ray redshift solutions taking advantage of the main features in obscured AGN spectra, like the Fe 6.4 keV K$\mathrm{\alpha}$ emission line, the 7.1 keV Fe absorption edge and the photoelectric absorption cut-off. The significance of such features is investigated through spectral simulations, and the derived X-ray redshift solutions are then compared with photometric redshifts. Both photometric and X-ray redshifts are derived for 33 sources. When multiple solutions are derived by any method, we find that combining the redshift solutions of the two techniques improves the rms by a factor of two. Using our redshift estimates ($0.1\lesssim z \lesssim 4$), we derived absorbing column densities in the range $\sim 10^{22}-10^{24}$ cm$^{-2}$ and absorption-corrected, 2-10 keV rest-frame luminosities between $\sim 10^{42}$ and $10^{45}$ erg s$^{-1}$, with median values of $N_H = 1.7 \times 10^{23}$ cm$^{-2}$ and $L_{\mathrm{2-10\, keV}} = 8.3\times10^{43}$ erg s$^{-1}$, respectively. Our results suggest that the adopted procedure can be applied to current and future X-ray surveys, for sources detected only in the X-rays or that have uncertain photometric or single-line spectroscopic redshifts.Comment: 22 pages, 18 figure

X-ray properties and obscured fraction of AGN in the J1030 Chandra field

The 500ks Chandra ACIS-I observation of the field around the $z=6.31$ quasar SDSS J1030+0524 is currently the 5th deepest extragalactic X-ray survey. The rich multi-band coverage of the field allowed for an effective identification and redshift determination of the X-ray source counterparts: to date a catalog of 243 extragalactic X-ray sources with either a spectroscopic or photometric redshift estimate in the range $z\approx0-6$ is available over a 355 arcmin$^2$ area. Given its depth and the multi-band information, this catalog is an excellent resource to investigate X-ray spectral properties of distant Active Galactic Nuclei (AGN) and derive the redshift evolution of their obscuration. We performed a thorough X-ray spectral analysis for each object in the sample, measuring its nuclear column density $N_{\rm H}$ and intrinsic (de-absorbed) 2-10 keV rest-frame luminosity, $L_{2-10}$. Whenever possible, we also used the presence of the Fe K$_\alpha$ emission line to improve the photometric redshift estimates. We measured the fractions of AGN hidden by column densities in excess of $10^{22}$ and $10^{23}$cm$^{-2}$ ($f_{22}$ and $f_{23}$, respectively) as a function of $L_{2-10}$ and redshift, and corrected for selection effects to recover the intrinsic obscured fractions. At $z\sim 1.2$, we found $f_{22}\sim0.7-0.8$ and $f_{23}\sim0.5-0.6$, respectively, in broad agreement with the results from other X-ray surveys. No significant variations with X-ray luminosity were found within the limited luminosity range probed by our sample (log$L_{2-10}\sim 42.8-44.3$). When focusing on luminous AGN with log$L_{2-10}\sim44$ to maximize the sample completeness up to large cosmological distances, we did not observe any significant change in $f_{22}$ or $f_{23}$ over the redshift range $z\sim0.8-3$. Nonetheless, the obscured fractions we measure are significantly higher than ...Comment: A&A, in pres

VizieR Online Data Catalog: Spectrum of QSO XMMC 2028 (Brusa+, 2015)

Observations of the CO(3-2) transition of XID2028, redshifted to 2mm, obtained with the PdBI Interferometer. Dates of observations: 31-May, 1, 6, June 2014. XID2028 was observed with receivers tuned to a frequency of 133.37GHz, corresponding to the expected frequency of the CO(3-2) emission line, with the PdBI array in the (D) configuration. The continuum is not detected with a 3σ upper limit on its flux of 0.3mJy

Redshift identification of X-ray selected active galactic nuclei in the J1030 field: searching for large-scale structures and high-redshift sources

We publicly release the spectroscopic and photometric redshift catalog of the sources detected with Chandra in the field of the $z$=6.3 quasar SDSS J1030+0525. This is currently the fifth deepest X-ray field, and reaches a 0.5-2 keV flux limit $f_{\rm 0.5-2}$=6$\times$10$^{-17}$ erg s$^{-1}$ cm$^{-2}$. By using two independent methods, we measure a photometric redshift for 243 objects, while 123 (51%) sources also have a spectroscopic redshift, 110 of which coming from an INAF-Large Binocular Telescope (LBT) Strategic Program. We use the spectroscopic redshifts to determine the quality of the photometric ones, and find it in agreement with that of other X-ray surveys which used a similar number of photometric data-points. In particular, we measure a sample normalized median absolute deviation $\sigma_{NMAD}$=1.48||$z_{phot}$-$z_{spec}$||/(1+$z_{spec}$)=0.065. We use these new spectroscopic and photometric redshifts to study the properties of the Chandra J1030 field. We observe several peaks in our spectroscopic redshift distribution between $z$=0.15 and $z$=1.5, and find that the sources in each peak are often distributed across the whole Chandra field of view. This evidence confirms that X-ray selected AGN can efficiently track large-scale structures over physical scales of several Mpc. Finally, we computed the Chandra J1030 $z>$3 number counts: while the spectroscopic completeness at high-redshift of our sample is limited, our results point towards a potential source excess at $z\geq$4, which we plan to either confirm or reject in the near future with dedicated spectroscopic campaigns

A project about Game Based Learning on Urban Sustainability

SUSTAIN is an ERASMUS+ project with an innovative perspective on urban transportation. Its target is to promote the importance of sustainability on the everyday problem of urban transportation among the students o f higher education, which are the policy makers o f tomorrow. In order to achieve its goals, the research team will develop a course that will b e based on an interactive game with an analytical style of education. This game will allow students to learn about transportation sustainability and societal metabolism through playing. In addition, the research team will develop small and illustrative simulation models, which will make the definitions more concrete and allow students to experiment in a consequence-free environmen

X-ray properties and obscured fraction of AGN in the J1030

The 500ks Chandra ACIS-I observation of the field around the z = 6.31 quasar SDSS J1030+0524 is currently the fifth deepest extragalactic X-ray survey. The rich multi-band coverage of the field allowed an effective identification and redshift determination of the X-ray source counterparts; to date, a catalog of 243 extragalactic X-ray sources with either a spectroscopic or photometric redshift estimate in the range z ≈ 0 − 6 is available over an area of 355 arcmin2. Given its depth and the multi-band information, this catalog is an excellent resource to investigate X-ray spectral properties of distant active galactic nuclei (AGN) and derive the redshift evolution of their obscuration. We performed a thorough X-ray spectral analysis for each object in the sample, and measured its nuclear column density NH and intrinsic (de-absorbed) 2–10 keV rest-frame luminosity, L2 − 10. Whenever possible, we also used the presence of the Fe Kα emission line to improve the photometric redshift estimates. We measured the fractions of AGN hidden by column densities in excess of 1022 and 1023 cm−2 (f22 and f23, respectively) as a function of L2 − 10 and redshift, and corrected for selection effects to recover the intrinsic obscured fractions. At z ∼ 1.2, we found f22 ∼ 0.7 − 0.8 and f23 ∼ 0.5 − 0.6, respectively, in broad agreement with the results from other X-ray surveys. No significant variations in X-ray luminosity were found within the limited luminosity range probed by our sample (log L2 − 10 ∼ 42.8 − 44.3). When focusing on luminous AGN with log L2 − 10 ∼ 44 to maximize the sample completeness up to large cosmological distances, we did not observe any significant change in f22 or f23 over the redshift range z ∼ 0.8 − 3. Nonetheless, the obscured fractions we measure are significantly higher than is seen in the local Universe for objects of comparable intrinsic luminosity, pointing toward an increase in the average AGN obscuration toward early cosmic epochs, as also observed in other X-ray surveys. We finally compared our results with recent analytic models that ascribe the greater obscuration observed in AGN at high redshifts to the dense interstellar medium (ISM) of their hosts. When combined with literature measurements, our results favor a scenario in which the total column density of the ISM and the characteristic surface density of its individual clouds both increase toward early cosmic epochs as NH, ISM∝(1 + z)δ, with δ ∼ 3.3 − 4 and Σc, * ∝ (1 + z)2, respectively

A systematic search for warm molecular gas in AGN and star forming galaxies at z=2 with MIRI

Feedback from Active Galactic Nuclei (AGN) have become the cornerstones of cosmological hydrodynamical simulations and they are believed to regulate the star formation in their host galaxies. A promising way to gauge the impact of AGN on the interstellar medium is by tracing their molecular gas content, as the gas experiences an immediate impact of the radiation, jets or outflows from the AGN, compared to star formation. Recent ALMA observations targeting CO emission in mass-matched sample of AGN and non-AGN host galaxies at high redshift have suggested that AGN display lower cold molecular gas content compared to their non-AGN counterparts. One of the hypothesis to explain this difference is the molecular gas in AGN host galaxies could be present in the warm molecular gas phase, traced using rest-frame near-infrared ro-vibrational transitions. This proposal aims to trace warm molecular gas via rest-frame H2 2.12 um transition in a mass-matched sample of AGN and non-AGN host galaxies at z~2.2 using MIRI/MRS. The selected sample is complemented by ground-based ionised gas and cold molecular gas observations. We will test if AGN host galaxies show a systematic difference in their warm molecular gas content compared to the non-AGN galaxies. We will also compute the total gas mass (ionised+molecular) in these galaxies which will provide a key input to current models of AGN feedback...

JWST/MIRI unravels the impact of AGN feedback on star-formation at cosmic noon

Detailed 3D zoom-in hydrodynamical simulations predicted a wide range of possible effects that energetic AGN-driven outflows have on their galaxy host's gas content: from no impact on to significant destruction of dense gas clouds in the nucleus and rapid suppression of star-formation. Observations are therefore key to determine which theoretical scenario is correct; however, they have been severely limited, prior of the JWST era, by their inability to have a reliable tracer of recent (<10 Myr) star-formation in luminous (log(Lbol)=45-46 erg s-1) AGN at z~2. With JWST/MIRI, we will ovecome this limitation by using the PAH[6.2 micron] emission to reliably trace, in a spatially resolved fashion, the recent star-formation. We target four AGN at z~2 with already identified ~6kpc wide ionized outflows based on deep SINFONI-AO observations. We will combine the MIRI PAH maps with the already available ionized outflow maps, as traced by [OIII], and ALMA maps tracing star-formation on ~100 My timescales (from rest-frame FIR continuum observations). This unique set of observations will allow us to answer the following questions: 1) are these AGN outflows able to rapidly suppress star-formation? 2) are these AGN outflows driven by radiation pressure on dust or are thermally driven?..