Rejected Candidates

Table 4: Rejected Candidates

ID	RA	Dec	Slope	$\log_{10} { L_{mIR} \over L_\odot }$	$f$	Spectral Energy Distribution [ $\log_{10} (\lambda L_\lambda/$L$_\odot)$]
			($a$)			[3.6]	[4.5]	[5.8]	[8.0]	[24]	[70]	[160]
M81-1	149.21474	69.12843	0.56	5.50	0.55	5.46	5.55	5.61	5.66	5.46	$<$5.28	$<$5.81
M81-2	148.91331	69.29649	0.22	5.06	0.54	5.21	5.15	4.95	5.33	5.13	$<$5.53	$<$5.97
M81-3	149.25626	68.91674	0.66	5.43	0.53	5.37	5.45	5.57	5.59	5.58	$<$5.50	$<$5.60
M81-4	149.15222	69.00780	0.61	5.08	0.53	5.08	5.09	5.19	5.28	5.30	$<$5.63	$<$6.58
M81-8	149.17365	68.80576	1.14	5.42	0.47	5.30	5.32	5.57	5.66	5.60	$<$5.51	$<$5.60
M81-9	148.85034	69.24746	1.76	5.45	0.40	5.18	5.38	5.45	5.83	5.52	$<$6.46	$<$6.27
M81-13	148.99657	69.26839	1.74	5.03	0.31	4.90	4.85	4.78	5.54	5.10	$<$6.14	$<$5.99
N247-2	11.90806	$-$20.51950	1.35	5.10	0.36	5.13	4.85	5.01	5.55	5.46	$<$6.89	...
N7793-2	359.47302	$-$32.47820	0.62	5.37	0.51	5.39	5.33	5.49	5.57	5.84	$<$5.99	$<$6.00
N7793-5	359.34467	$-$32.62253	0.76	5.15	0.42	5.33	4.96	5.05	5.54	5.24	$<$6.13	$<$6.47
N7793-7	359.46878	$-$32.63801	1.17	5.04	0.37	5.09	4.87	4.87	5.49	5.59	$<$6.08	$<$6.80

Of the 11 rejected candidates, six are AGNs or galaxies with a redshift measurement. Four have been photometrically classified as galaxies by the SDSS survey (Abazajian et al.2009) and visual inspections of the SDSS images find diffuse extended sources consistent with this classification. One of these sources is also 04 away from a radio and X-ray source and is likely a low redshift AGN. One candidate is a well-resolved galaxy in HST images. The SEDs of the rejected candidates are shown in Figure8 and their luminosities, SED slope, and $f$ are listed in Table4. In detail, we find that:

• M81-1 is an AGN. It is 0362 from a quasar at $z=0.605$ (Richards et al.2009).

• M81-2 is an AGN. It lies 04 from a radio and X-ray source (Flesch2010) and is classified as a galaxy by SDSS (Abazajian et al.2009). Visual inspection of the SDSS image also shows an extended source consistent with this classification.

• M81-3 is an AGN. It is 038 from a quasar at $z=1.29683$ (Schneider et al.2010).

• M81-4 is an AGN. It is 065 from a quasar at $z=1.97519$ (Schneider et al.2010).

• M81-8, M81-9, and M81-13 are classified as galaxies by SDSS (Abazajian et al.2009) and visual inspections of the SDSS images finds extended sources consistent with these classifications.

• N247-2 is a galaxy at $z=0.02089$ (Jones et al.2009).

• N7793-2 is unambiguously a galaxy in HST images (Figure10, bottom panel).

• N7793-5 is a galaxy at $z=0.0614$ (Jones et al.2009).

• N7793-7 is an AGN. It is 15 from a QSO at $z=0.071$ (Véron-Cetty & Véron2010).

While the astrometric matches are sometimes imperfect, we are dealing with objects with such low surface densities that a mismatch is extraordinarily unlikely. Essentially, this search recapitulates aspects of the Kozowski et al. (2010) search for quasars behind the Magellanic clouds as red mid-IR sources following the extragalactic mid-IR search criteria of Stern et al. (2005). The red mid-IR colors created by the power-law SEDs of quasars mimic aspects of the red SEDs of dusty stars.