J/ApJ/793/101 CANDELS z∼2 galaxy properties (Trump+, 2014)
No more active galactic nuclei in clumpy disks than in smooth galaxies at z∼2
in CANDELS/3D-HST.
Trump J.R., Barro G., Juneau S., Weiner B.J., Luo B., Brammer G.B.,
Bell E.F., Brandt W.N., Dekel A., Guo Y., Hopkins P.F., Koo D.C.,
Kocevski D.D., McIntosh D.H., Momcheva I., Faber S.M., Ferguson H.C.,
Grogin N.A., Kartaltepe J., Koekemoer A.M., Lotz J., Maseda M., Mozena M.,
Nandra K., Rosario D.J., Zeimann G.R.
<Astrophys. J., 793, 101 (2014)>
=2014ApJ...793..101T 2014ApJ...793..101T (SIMBAD/NED BibCode)
ADC_Keywords: Galaxy catalogs ; Active gal. nuclei ; Redshifts ;
Photometry, H-beta
Keywords: galaxies: active - galaxies: nuclei - galaxies: Seyfert -
galaxies: structure
Abstract:
We use CANDELS imaging, 3D-HST spectroscopy, and Chandra X-ray data to
investigate if active galactic nuclei (AGNs) are preferentially fueled
by violent disk instabilities funneling gas into galaxy centers at
1.3<z<2.4. We select galaxies undergoing gravitational instabilities
using the number of clumps and degree of patchiness as proxies. The
CANDELS visual classification system is used to identify 44 clumpy
disk galaxies, along with mass-matched comparison samples of smooth
and intermediate morphology galaxies. We note that despite being
mass-matched and having similar star formation rates, the smoother
galaxies tend to be smaller disks with more prominent bulges compared
to the clumpy galaxies. The lack of smooth extended disks is probably
a general feature of the z∼2 galaxy population, and means we cannot
directly compare with the clumpy and smooth extended disks observed at
lower redshift. We find that z∼2 clumpy galaxies have slightly
enhanced AGN fractions selected by integrated line ratios (in the
mass-excitation method), but the spatially resolved line ratios
indicate this is likely due to extended phenomena rather than nuclear
AGNs. Meanwhile, the X-ray data show that clumpy, smooth, and
intermediate galaxies have nearly indistinguishable AGN fractions
derived from both individual detections and stacked non-detections.
The data demonstrate that AGN fueling modes at z∼1.85 - whether
violent disk instabilities or secular processes - are as efficient in
smooth galaxies as they are in clumpy galaxies.
Description:
We select a sample of 44 clumpy galaxies from the Great Observatories
Origins Deep Survey South (GOODS-S; Giavalisco et al.
2004ApJ...600L..93G 2004ApJ...600L..93G, Cat. II/261) region of CANDELS. For comparison,
we also construct mass-matched samples of 41 smooth (non-clumpy) and
35 intermediate galaxies. All galaxies have H<24 (to ensure reliable
classification of clumpiness) and have [O III] detected at the
3σ level (for reliable AGN line ratio diagnostics) in the
redshift range 1.3<z<2.4. Each morphology category has a median
redshift of z=1.85. Redshifts and emission line measurements come from
HST/WFC3 grism spectroscopy taken by the 3D-HST survey (Brammer et al.
2012ApJS..200...13B 2012ApJS..200...13B).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 79 121 Galaxy Properties
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See also:
II/261 : GOODS initial results (Giavalisco+, 2004)
J/ApJS/195/10 : The CDF-S survey: 4Ms source catalogs (Xue+, 2011)
J/ApJS/203/24 : Structural parameters of galaxies in CANDELS
(van der Wel+, 2012)
J/ApJS/207/24 : GOODS-S CANDELS multiwavelength catalog (Guo+, 2013)
J/ApJS/214/24 : 3D-HST+CANDELS catalog (Skelton+, 2014)
J/ApJ/801/97 : GOODS-S + UDS stellar mass catalogs from CANDELS
(Santini+, 2015)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- ID CANDELS identifier (NNNNN) from
Guo et al., 2013, J/ApJS/207/24
7 A1 --- f_ID [ab] Flag on ID (1)
9- 16 A8 --- Class Morphology classification
18- 28 F11.8 deg RAdeg Right Ascension in decimal degrees (J2000)
30- 41 F12.8 deg DEdeg Declination in decimal degrees (J2000)
43- 46 F4.2 --- z Redshift
48 A1 --- l_Hb Upper limit flag on Hb
49- 54 F6.2 10-21W/m2 Hb Hβ line flux; 1e-18 erg/s/cm2 (2)
56- 60 F5.2 10-21W/m2 e_Hb Error in Hβ (2)
62- 67 F6.2 10-21W/m2 O3 The [OIII] (5007Å) line flux;
1e-18 erg/s/cm2
69- 73 F5.2 10-21W/m2 e_O3 Error in O3
75- 79 F5.2 [Msun] logMass Log stellar mass
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Note (1): Flag as follows:
a = X-ray detected, but in the soft band only and consistent with emission
from a star-forming galaxy (Xue et al. 2011, J/ApJS/195/10).
b = X-ray detected and classified as an AGN by Xue et al.
(2011, J/ApJS/195/10).
Note (2): A line ratio error of zero indicate a 1σ upper limit.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 19-Apr-2017