Browsing by Author "Schreiber, N. M. Foerster"

Now showing 1 - 4 of 4
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    Enhanced star formation rates in AGN hosts with respect to inactive galaxies from PEP-Herschel observations
    (2012) Santini, P.; Rosario, D. J.; Shao, L.; Lutz, D.; Maiolino, R.; Alexander, D. M.; Altieri, B.; Andreani, P.; Aussel, H.; Bauer, F. E.; Berta, S.; Bongiovanni, A.; Brandt, W. N.; Brusa, M.; Cepa, J.; Cimatti, A.; Daddi, E.; Elbaz, D.; Fontana, A.; Schreiber, N. M. Foerster; Genzel, R.; Grazian, A.; Le Floc'h, E.; Magnelli, B.; Mainieri, V.; Nordon, R.; Garcia, A. M. Perez; Poglitsch, A.; Popesso, P.; Pozzi, F.; Riguccini, L.; Rodighiero, G.; Salvato, M.; Sanchez-Portal, M.; Sturm, E.; Tacconi, L. J.; Valtchanov, I.; Wuyts, S.
    We compare the average star formation (SF) activity in X-ray selected AGN hosts with a mass-matched control sample of inactive galaxies, including both star forming and quiescent sources, in the 0.5 < z < 2.5 redshift range. Recent observations carried out by PACS, the 60-210 mu m photometric camera on board the Herschel Space Observatory, in GOODS-S, GOODS-N and COSMOS allow us to obtain an unbiased estimate of the far-IR luminosity, and hence of the SF properties, of the two samples. Accurate AGN host stellar mass estimates are obtained by decomposing their total emission into the stellar and the nuclear components. We report evidence of a higher average SF activity in AGN hosts with respect to the control sample of inactive galaxies. The level of SF enhancement is modest (similar to 0.26 dex at similar to 3 sigma confidence level) at low X-ray luminosities (L-X less than or similar to 10(43.5) erg s(-1)) and more pronounced (0.56 dex at >10 sigma confidence level) in the hosts of luminous AGNs. However, when comparing to star forming galaxies only, AGN hosts are found broadly consistent with the locus of their "main sequence". We investigate the relative far-IR luminosity distributions of active and inactive galaxies, and find a higher fraction of PACS detected, hence normal and highly star forming systems among AGN hosts. Although different interpretations are possible, we explain our findings as a consequence of a twofold AGN growth path: faint AGNs evolve through secular processes, with instantaneous AGN accretion not tightly linked to the current total SF in the host galaxy, while the luminous AGNs co-evolve with their hosts through periods of enhanced AGN activity and star formation, possibly through major mergers. While an increased SF activity with respect to inactive galaxies of similar mass is expected in the latter, we interpret the modest SF offsets measured in low-L-X AGN hosts as either a) generated by non-synchronous accretion and SF histories in a merger scenario or b) due to possible connections between instantaneous SF and accretion that can be induced by smaller scale (non-major merger) mechanisms. Far-IR luminosity distributions favour the latter scenario.
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    The ALMA-CRISTAL survey Discovery of a 15 kpc-long gas plume in a z=4.54 Lyman-α blob
    (2024) Solimano, M.; Gonzalez-Lopez, J.; Aravena, M.; Herrera-Camus, R.; De Looze, I.; Schreiber, N. M. Foerster; Spilker, J.; Tadaki, K.; Assef, R. J.; Barcos-Munoz, L.; Davies, R. L.; Diaz-Santos, T.; Ferrara, A.; Fisher, D. B.; Guaita, L.; Ikeda, R.; Johnston, E. J.; Lutz, D.; Mitsuhashi, I.; Moya-Sierralta, C.; Relano, M.; Naab, T.; Posses, A. C.; Telikova, K.; Uebler, H.; van der Giessen, S.; Veilleux, S.; Villanueva, V.
    Massive star-forming galaxies in the high-redshift universe host large reservoirs of cold gas in their circumgalactic medium (CGM). Traditionally, these reservoirs have been linked to diffuse H I Lyman-alpha (Ly alpha) emission extending beyond approximate to 10 kpc scales. In recent years, millimeter and submillimeter observations have started to identify even colder gas in the CGM through molecular and/or atomic tracers such as the [C II] 158 mu m transition. In this context, we studied the well-known J1000+0234 system at z = 4.54 that hosts a massive dusty star-forming galaxy (DSFG), a UV-bright companion, and a Ly alpha blob. We combined new ALMA [C II] line observations taken by the CRISTAL survey with data from previous programs targeting the J1000+0234 system, and achieved a deep view into a DSFG and its rich environment at a 0 ''. 2 = 1.3 kpc resolution. We identified an elongated [C II]-emitting structure with a projected size of 15 kpc stemming from the bright DSFG at the center of the field, with no clear counterpart at any other wavelength. The plume is oriented approximate to 40 degrees away from the minor axis of the DSFG, and shows significant spatial variation of its spectral parameters. In particular, the [C II] emission shifts from 180 km s(-1 )to 400 km s(-1) between the bottom and top of the plume, relative to the DSFG's systemic velocity. At the same time, the line width starts at 400 - 600 km s(-1) but narrows down to 190 km s(-1) at the top end of the plume. We discuss four possible scenarios to interpret the [C II] plume: a conical outflow, a cold accretion stream, ram pressure stripping, and gravitational interactions. While we cannot strongly rule out any of these with the available data, we disfavor the ram pressure stripping scenario due to the requirement of special hydrodynamic conditions.
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    The ALMA-CRISTAL Survey: Spatially Resolved Star Formation Activity and Dust Content in 4 < z < 6 Star-forming Galaxies
    (2024) Li, Juno; Da Cunha, Elisabete; Gonzalez-Lopez, Jorge; Aravena, Manuel; De Looze, Ilse; Schreiber, N. M. Foerster; Herrera-Camus, Rodrigo; Spilker, Justin; Tadaki, Ken-ichi; Barcos-Munoz, Loreto; Battisti, Andrew J.; Birkin, Jack E.; Bowler, Rebecca A. A.; Davies, Rebecca; Diaz-Santos, Tanio; Ferrara, Andrea; Fisher, Deanne B.; Hodge, Jacqueline; Ikeda, Ryota; Killi, Meghana; Lee, Lilian; Liu, Daizhong; Lutz, Dieter; Mitsuhashi, Ikki; Naab, Thorsten; Posses, Ana; Relano, Monica; Solimano, Manuel; Uebler, Hannah; van der Giessen, Stefan Anthony; Villanueva, Vicente
    Using a combination of Hubble Space Telescope (HST), JWST, and Atacama Large Millimeter/submillimeter Array (ALMA) data, we perform spatially resolved spectral energy distributions (SED) fitting of fourteen 4 < z < 6 ultraviolet (UV)-selected main-sequence galaxies targeted by the ALMA Large Program [C ii] Resolved ISM in Star-forming Galaxies. We consistently model the emission from stars and dust in similar to 0.5-1 kpc spatial bins to obtain maps of their physical properties. We find no offsets between the stellar masses (M-*) and star formation rates (SFRs) derived from their global emission and those from adding up the values in our spatial bins, suggesting there is no bias of outshining by young stars on the derived global properties. We show that ALMA observations are important to derive robust parameter maps because they reduce the uncertainties in L-dust (hence, A(V) and SFR). Using these maps, we explore the resolved star-forming main sequence for z similar to 5 galaxies, finding that this relation persists in typical star-forming galaxies in the early Universe. We find less obscured star formation where the M-* (and SFR) surface densities are highest, typically in the central regions, contrary to the global relation between these parameters. We speculate this could be caused by feedback driving gas and dust out of these regions. However, more observations of IR luminosities with ALMA are needed to verify this. Finally, we test empirical SFR prescriptions based on the UV+IR and [C ii] line luminosity, finding they work well at the scales probed (approximately kiloparsec). Our work demonstrates the usefulness of joint HST-, JWST-, and ALMA-resolved SED modeling analyses at high redshift.
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    The mean star formation rate of X-ray selected active galaxies and its evolution from z ∼ 2.5: results from PEP-Herschel
    (2012) Rosario, D. J.; Santini, P.; Lutz, D.; Shao, L.; Maiolino, R.; Alexander, D. M.; Altieri, B.; Andreani, P.; Aussel, H.; Bauer, F. E.; Berta, S.; Bongiovanni, A.; Brandt, W. N.; Brusa, M.; Cepa, J.; Cimatti, A.; Cox, T. J.; Daddi, E.; Elbaz, D.; Fontana, A.; Schreiber, N. M. Foerster; Genzel, R.; Grazian, A.; Le Floch, E.; Magnelli, B.; Mainieri, V.; Netzer, H.; Nordon, R.; Garcia, I. Perez; Poglitsch, A.; Popesso, P.; Pozzi, F.; Riguccini, L.; Rodighiero, G.; Salvato, M.; Sanchez-Portal, M.; Sturm, E.; Tacconi, L. J.; Valtchanov, I.; Wuyts, S.
    We study relationships between star-formation rate (SFR) and the accretion luminosity and nuclear obscuration of X-ray selected active galactic nuclei (AGNs) using a combination of deep far-infrared (FIR) and X-ray data in three key extragalactic survey fields (GOODS-South, GOODS-North and COSMOS), as part of the PACS Evolutionary Probe (PEP) program. The use of three fields with differing areas and depths enables us to explore trends between the global FIR luminosity of the AGN hosts and the luminosity of the active nucleus across 4.5 orders of magnitude in AGN luminosity (L-AGN) and spanning redshifts from the Local Universe to z = 2.5. Using imaging from the Herschel/PACS instrument in 2-3 bands, we combine FIR detections and stacks of undetected objects to arrive at mean fluxes for subsamples in bins of redshift and X-ray luminosity. We constrain the importance of AGN-heated dust emission in the FIR and confirm that the majority of the FIR emission of AGNs is produced by cold dust heated by star-formation in their host galaxies.